Methods and devices for termination

ABSTRACT

Devices and methods used in termination of a tissue tightening procedure are described. Termination includes the cinching of a tether to tighten the tissue, locking the tether to maintain tension, and cutting excess tether. In procedures involving anchors secured to the tissue, the tether is coupled to the anchors and the tissue is tightened via tension applied to the anchors by cinching the tether. In general, the devices and methods can be used in minimally invasive surgical procedures, and can be applied through small incisions or intravascularly. A method for tightening tissue by fixedly coupling a first anchor to a tether and slidably coupling a second anchor to the tether, securing both anchors to the tissue, applying tension to the tether intravascularly, fixedly coupling the tether to the second anchor, and cutting the tether is described. The tissue to be tightened can comprise heart tissue, in particular heart valve annulus tissue. Various devices and methods for locking the tether in place and cutting excess tether are described.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of U.S. Ser. No. 11/232,190,filed Sep. 20, 2005, which is a continuation-in-part of U.S. Ser. No.10/792,681, filed Mar. 2, 2004, which claims the benefit of U.S. Ser.No. 60/459,735, filed on Apr. 1, 2003, U.S. Ser. No. 60/462,502, filedon Apr. 10, 2003, and U.S. Ser. No. 60/524,922, filed on Nov. 24, 2003,and which is a continuation-in-part of U.S. Ser. No. 10/741,130, filedon Dec. 19, 2003, which is a continuation-in-part of U.S. Ser. No.10/656,797, filed on Sep. 4, 2003, and is a continuation-in-part of U.S.Ser. No. 10/461,043, filed on Jun. 13, 2003, the latter of which claimsthe benefit of U.S. Ser. No. 60/388,935, filed on Jun. 13, 2002, U.S.Ser. No. 60/429,288, filed on Nov. 25, 2002, U.S. Ser. No. 60/445,890,filed on Feb. 6, 2003, and U.S. Ser. No. 60/462,502, filed on Apr. 10,2003, the disclosures of which are herein incorporated by reference intheir entirety.

FIELD

The methods and devices described herein relate generally to medicaldevices and methods, and more specifically to devices and methods forenhancing tissue repair using minimally invasive surgical techniques,especially for use in cardiovascular valve repair.

BACKGROUND

Advances have been made in techniques and tools for use in minimallyinvasive surgery that can be performed through small incisions orintravascularly. For example, improvements have been made recently toreduce the invasiveness of cardiac surgery. To avoid open procedures,such as open, stopped-heart surgery, which can lead to high patientmorbidity and mortality, devices and methods have been developed foroperating through small incision, for operating on a beating heart, andfor performing cardiac procedures via intravascular or intravascularaccess. For many minimally invasive surgery techniques, significantchallenges include positioning the treatment device or devices in adesired location for performing the procedure and deploying thetreatment into or on the target tissue.

Heart valve repair can benefit from less invasive surgical techniques.Traditional treatment of heart valve stenosis or regurgitation, such asmitral or tricuspic regurgitation, typically involves an open-heartsurgical procedure to replace or repair the valve. Valve repairprocedures usually involve annuloplasty, which is a set of techniquesdesigned to restore the valve annulus shape and strengthen the annulus.Conventional annuloplasty surgery generally requires a thoracotomy (alarge incision into a patient's thorax), and sometimes a medianstemotomy (an incision through a patient's sternum). These open-heart,open-chest procedures routinely involve placing the patient on aheart-lung bypass machine for long periods of time so that the patient'sheart and lungs can be stopped during the procedure. In addition, valverepair and replacement is typically technically challenging and requiresa substantial incision through a heart wall to access the valve. Manypatients such as elderly patients, children, patients with complicatingconditions such as comorbid medical conditions or those having undergoneother surgical procedures, and patients with heart failure, are notconsidered candidates for heart valve surgery because of the high riskinvolved.

Minimally invasive procedures are typically performed endoscopicallythrough catheters, through small incisions or intravascularly.Instruments such as graspers, dissectors, clip appliers, lasers,cauterization devices and clamps are routinely used endoscopically, withan endoscope used for visualizing the procedure. When a surgeon desiresto bring pieces of two tissue together, the surgeon typically threads asuture through the two pieces of tissue, applies tension, and ties offor knots the suture to maintain the tension. However, during endoscopicsurgery, the manipulation required when knotting or tying suturematerial can be difficult because of severely restricted space.

Previously, there have been attempts to maintain tension in tissue byusing staples, clips, clamps, or other fasteners to obviate the need forsuturing. However, these methods do not provide adjustable tension suchas is available when a surgeon uses suture. U.S. Pat. Nos. 5,520,702 and5,643,289 describe deformable cylindrical tubes that can be applied overa loop of suture. After a suture is adjusted to a desired tension, thesuture is looped, and a deployment gun applies a deformable tube overthe suture loop and crimps it so that it clamps down on the suture.After the loop is secured with a crimp, a separate cutting member ortool can be used to cut the excess suture material. U.S. Pat. No.6,099,553 also describes deformable crimps that can be applied over theends of sutures to fix them into place. Similar crimping devices thatoperate to mechanically fasten suture together and cut away excesstether are provided as TI-KNOT® knot replacement systems by LSISolutions®. However, with crimping schemes, the suture may still slipthrough crimps and lose tension, especially if the suture has a smalldiameter, if the suture is made of a material susceptible to slippage,such as metal or TEFLON® fluoropolymer, or if the crimp isinsufficiently deformed. U.S. Publication No. 2003/0167071 describesfasteners made from shape memory materials that can be applied tosutures to avoid tying knots in catheter-based procedures. U.S. Pat.Nos. 6,409,743 and 6,423,088 describe fusible collars that can be usedin place of knots in securing sutures. These fusible collars require anexternal source of energy be locally applied to the collar withoutdamaging surrounding tissue for the fusing process.

Devices and methods for less-invasive repair of cardiac valves have beendescribed. In heart valve repair procedures, it is often desired for aphysician to secure one or more treatment devices to valve annulustissue. Annular tissue tends to be more fibrous than muscular or valveleaflet tissue, and thus can be more suitable tissue for securingtreatment devices such as anchors to treat a heart valve. Devices andmethods for positioning anchor delivery devices are described in U.S.Patent Application Ser. Nos. 60/445,890, 60/459,735, 60/462,502,60/524,922, 10/461,043, 10/656,797, 10/741,130 and 10/792,681, whichwere previously incorporated by reference. For example, these referencesdescribe devices and methods for exposing, stabilizing and/or performinga procedure on a heart valve annulus.

Many treatments, including annuloplasty, involve tightening of tissue.For some tissue tightening procedures, anchors coupled to a suture areembedded in tissue, and the suture is then cinched to tighten the tissuevia the anchors. Examples of devices and methods for such proceduresapplied to heart valve repair are provided in U.S. patent applicationSer. Nos. 10/656,797, 10/741,130 and 10/792,681.

Improved methods and devices for locking a suture to maintain tension inthe suture are desired, especially in minimally invasive treatmentswhere surgical access is limited. For treatments involving tissueanchors, improved methods and devices are desired for locking a suturethat has been coupled with the anchors such that the suture does notmove relative to the last applied anchor. Also desired are improvedmethods and devices for severing excess suture so that it can beremoved.

BRIEF SUMMARY

Described herein are devices and methods for use in terminationprocedures during tissue tightening treatments. In general, terminationinvolves any one or all of the steps carried out when finishing a tissuetightening procedure, including: cinching a tether to tighten tissue;locking the cinching tether in place; and cutting off excess tether.Tissue anchors can be secured to the tissue to be tightened and thetether coupled to the anchors, so that cinching of the tether tightensthe tissue via the anchors.

In some variations, a method for tightening tissue is provided. A firstanchor is fixedly coupled to a tether, and a second anchor is slidablycoupled to the tether. Both anchors are secured to the tissue to betightened. Tension is applied to the tether intravascularly, the secondanchor is fixedly coupled to the tether, and the tether is cut.

In some variations, the anchors are secured to the tissueintravascularly. In some variations, the tissue includes heart tissue.For example, the tissue can include a heart valve annulus or a mitralvalve annulus.

A force having a component counter to the tensioning force applied tothe tether can be applied to the second anchor in some variations. Anintravascular device can be contacted with the second anchor to applythe force to the second anchor.

In some variations, a portion of the tether is loaded into anintravascular device after the anchors are secured to the tissue. Thetether can be captured with a loop to load it into the intravasculardevice. The tether can also be threaded through a feature in a rod, andthe rod can be inserted into the intravascular device. The features inthe rod can include openings, indents, grooves, slits, or the like.

In other variations, the tether can be fixedly coupled to the anchorintravascularly. In some variations, the tether is fixedly coupled tothe second anchor by clamping the tether to the second anchor. In othervariations, the tether can be fixedly coupled to the second anchor bydeforming the second anchor. In still other variations, the tether canbe fixedly coupled to the second anchor by applying an adhesive to thetether.

In some variations, the tether is fixedly coupled to the second anchorby providing a locking feature on the tether. The tether can be threadedthrough a feature on the second anchor, and the locking feature cannotpass through the feature on the second anchor in the direction towardthe first anchor. The locking feature can include protrusions that allowthe locking feature to slide along the tether in one direction only. Thelocking feature can include a knot. The locking feature can include awasher through which the tether passes and a knot on the tether, whichcannot pass through the washer. In some variations, the locking featurecan pass through the feature on the second anchor through which thetether passes in the direction away from the first anchor. The featureon the second anchor can include an eyelet.

In some variations, the locking feature is clamped to the tether. Thetether can be clamped between an expanded deformable mesh and the innerwall of a tube. The tether can be clamped by applying a force to atleast partially unkink a kinked tube, passing the tether through thetube, and then releasing the force to re-kink the tube. In somevariations, the tether is clamped by applying a force to separate twosurfaces of the locking feature, passing the tether between thesurfaces, and releasing the force to clamp the tether between thesurfaces. The tether can be clamped by applying a force to cause twosurfaces of the locking feature to move together to clamp the tetherbetween the two surfaces. In other variations, the tether is passedthrough an opening in a deformable material, and the deformable materialis deformed to cause a dimension in the opening in the deformablematerial to decrease, thereby clamping the tether. The tether can beclamped by passing the tether through the locking feature and alteringthe path of the tether through the locking feature to increase thefrictional forces on the tether.

A locking feature (e.g., a clamp, lock, knot, or other tether-securingfeature) may be detachable from a delivery device. For example, alocking feature may be releasably (or detachably) connected to a tube,rod, or wire, etc. In one variation, the termination device comprises alocking feature that is detachably connected to a delivery tube. Otherfeatures may also be included as part of the termination device, includea tether cutter, a push rod (for detaching and/or activating the lockingfeature), etc.

In some variations, the cutting of the tether is performedintravascularly. In other variations, the tether is cut proximal to thesecond anchor. In still other variations, the tether is cut by shearingthe tether between two concentric tubes. One concentric tube can beadvanced with respect to the other concentric tube along the axis of thetubes. Alternatively, one concentric tube can be rotated with respect tothe other concentric tube about the axis of the tubes.

In some variations, the tether can be cut by passing the tether throughan opening in a tube and rotating a blade in a plane that intersects anaxis of the tube. In other variations, the tether can be cut bycontacting the tether with a cutting blade. In still other variations,the tether can be cut by passing the tether through a tube, inflating inthe tube a balloon to which one or more cutting blades are mounted androtating the balloon. In other variations, the tether can be cut byshearing the tether between two blades sharing a pivot.

In some variations, a single intravascular device can deploy theanchors, apply tension to the tether, fixedly couple the tether to thesecond anchor and cut the tether. In other variations, the same ordifferent intravascular device may be used to perform any step orcombination of steps in a method for tightening tissue that includessecuring to the tissue a first anchor fixedly coupled to a tether and asecond anchor slidably coupled to the tether, applying tension to thetether intravascularly, fixedly coupling the tether to the second anchorand cutting the tether.

In some variations, a termination device includes a detachable lockingfeature and a tether cutter. For example, the termination device maycomprise a tubular body that couples to a tether with a detachablelocking feature at the distal end of the termination device. Thetermination device may also include a tether cutter. In some variations,the tether cutter is located proximal to the detachable locking feature.In operation, the tether may be coupled to the detachable lockingfeature (e.g., by threading through a region of the detachable lockingfeature), and the locking feature may be positioned to secure the tether(e.g., abutting an anchor). The tether may be tensioned appropriately,and the locking feature can be locked and detached from the rest of thetermination device. The tether maybe cut either before or afterdetaching the locking feature. In some variations, the terminationdevice comprises a rod for locking the detachable locking feature and/orfor detaching the detachable locking feature.

Described herein are termination devices for locking an implantable andcinchable tether. The termination devices may include an elongate bodyand a locking feature releasably attached to the distal end of theelongate body. The locking feature is typically configured to couple tothe tether, and has an unsecured state (e.g., an “open” state in somevariations), wherein the tether may move with respect to the lockingfeature, and a secured state (e.g., a “closed state” in somevariations), wherein the tether is secured by the locking feature. Thetermination device may also include a tether cutter. For example, atether cutter may be located distally to the locking feature. (such as acutting tube within the elongate body). In some variations, the elongatebody is configured as a catheter.

In some variations, the termination device may also include a forceapplicator for releasing the locking feature from the rest of thetermination device. For example, the force applicator may comprise apush rod extending longitudinally within the elongate body of thetermination device. The termination device may also include a releasableattachment region between the locking feature and the elongate body thatcan be broken or detached to separate the locking feature of thetermination device from the rest of the device. The releasableattachment region may be a frangible region, and may be configured toseparate the locking feature from the elongate body when a force ofgreater than a predetermined load (e.g., about 2 lbs) is applied to thelocking feature. In some variations, the releasable attachment regioncomprises a perforated region. The releasable attachment region may alsobe formed by the connection between two regions made up of differentmaterials. For example, the locking feature may comprise a differentmaterial than the elongate body. The locking feature may also beseparated from the body of the termination device (e.g., catheter) by acutter. The cutter may be a sharp slot, hole, or edge attached to anelongate element that slides relative to the joint (e.g., the releasableattachment region), and thus cuts the joint. The cutter may also cut thejoint and the tether in a single motion.

Any appropriate locking feature may be used. In some variations, thelocking feature comprises a clamp. In some variations, the lockingfeature comprises a plug or inner tube that is configured to compressthe tether against a wall of the locking feature when the lockingfeature is in the secured state.

Also described herein are termination devices including an elongatebody, a locking feature releasably attached to the distal end of theelongate body (the locking feature configured to couple to the tether)and a tether cutter coupled to the elongate body, wherein the tethercutter may be activated to cut the tether.

Methods of securing a cinchable tether are also described. In somevariations, these methods may include the steps of coupling the tetherto a termination device (wherein the termination device comprises anelongate body and a locking feature releasably attached to the distalend of the elongate body, so that the locking feature can be coupled tothe tether), cinching the tether, and securing the tether with thelocking feature.

In some variations, the method of securing a cinchable tether may alsoinclude the step of cutting the tether (e.g., using a tether cutter,including a tether cutter that is part of the termination device). Themethod may also include the step of separating the locking feature fromthe elongate body. In some variations, the step of separating thelocking feature from the elongate body includes applying force toseparate the locking feature from the elongate body. The step ofapplying force may comprise pushing a push rod located at least partlywithin the elongate body.

BRIEF DESCRIPTION OF. THE DRAWINGS

FIG. 1 is a cross-sectional view of a heart with a flexible anchordelivery device being positioned for treatment of a mitral valveannulus, according to some embodiments.

FIGS. 2A-D are cross-sectional views of a portion of a heart,schematically showing positioning of a flexible device for treatment ofa mitral valve annulus, according to some embodiments.

FIG. 3 is a perspective view of a distal portion of an anchor deliverydevice, according to some embodiments.

FIG. 4 is a perspective view of a segment of a distal portion of ananchor delivery device, with anchors in an undeployed shape andposition.

FIG. 5 is a different perspective view of the segment of the deviceshown in FIG. 4.

FIG. 6 is a perspective view of a segment of a distal portion of ananchor delivery device, with anchors in a deployed shape and position.

FIGS. 7A-7E are cross-sectional views of an anchor delivery device,illustrating a method for delivering anchors to valve annulus tissue.

FIGS. 8A and 8B are top views of a plurality of anchors coupled to aself-deforming member or “backbone,” with the backbone shown in anundeployed shape and in a deployed shape.

FIGS. 9A-9C are various perspective views of a distal portion of aflexible anchor delivery device according to some embodiments.

FIGS. 10A-10F illustrate a method for applying anchors to a valveannulus and cinching the anchors to tighten the annulus, using an anchordelivery device according to some embodiments.

FIG. 11 shows a heart in cross-section with a guide catheter deviceadvanced through the aorta into the left ventricle according to someembodiments.

FIG. 12A-12F illustrate a method for advancing an anchor delivery deviceto a position for treating a heart valve according to some embodiments.

FIGS. 13A and 13B are side cross-sectional views of a guide catheterdevice for facilitating positioning of an anchor delivery deviceaccording to some embodiments.

FIGS. 14A and 14B are illustrative variations of devices and methods forloading tethers into catheters.

FIGS. 15A-H are additional variations of devices and methods for loadingtethers into catheters.

FIGS. 16A-E are illustrative examples of termination devices and methodsutilizing knots to fix a tether in place.

FIG. 17 illustrates an example of a termination method and device thatutilizes a tether comprising spaced apart protrusions to maintaintension on the tether.

FIGS. 18A-B illustrates additional examples of termination methods anddevices that utilize a tether comprising spaced apart protrusions tomaintain tension on the tether.

FIGS. 19A-C show variations of termination devices and methods thatinclude threading a tether through a tube that can be straight (to allowthe tether to slide) or kinked (to lock the tether into place).

FIGS. 20A-B show variations of termination devices and methods thatinclude threading a tether through a clamp that forces the tether into atortuous path to fix the tether in place.

FIGS. 21A-C show additional variations of termination devices andmethods that include threading a tether through a clamp that forces thetether into a tortuous path to fix the tether in place.

FIG. 22 shows a variation of a termination device utilizing clips orspring clips to lock a tether.

FIGS. 23A-C illustrate variations of termination devices and methodsthat utilize an expandable mesh element to fix a tether.

FIGS. 24A-B show examples of termination devices and methods thatincorporate threading a tether through protrusions that allow the tetherto slide in one direction, but not in the opposite direction.

FIG. 25 shows another example of a termination device as describedherein.

FIGS. 26A-B show examples of termination devices and methods thatinclude threading a tether through a compressible ring, and thencompressing the ring such that the inner dimension of the ring isreduced sufficiently to prevent the tether from sliding through thering.

FIG. 27 shows another example of a termination device and method thatincludes threading a tether through a compressible ring, and thencompressing the ring such that the inner dimension of the ring isreduced sufficiently to prevent the tether from sliding through thering.

FIGS. 28A-C show examples of termination devices and methods thatinclude threading a tether through a channel of a clamping device, andinserting an actuator that forces actuator elements into the channel toimpede slippage of the tether to lock the tether in place.

FIGS. 29A-F illustrate various examples of termination devices andmethods that utilize sharpened tubes to sever excess tether after thetether is locked into place.

FIGS. 30A-B show additional examples of termination devices and methodsthat utilize sharpened tubes to sever excess tether.

FIGS. 31A-D illustrate variations of tubular termination devices andmethods that can be used to cut excess tether after the tether is lockedinto place.

FIGS. 32A-B show other variations of tubular termination devices andmethods for cutting tether.

FIG. 33 illustrates variations of termination devices and methods thatutilize concentric tubes for cutting tether.

FIGS. 34A-D show variations of termination devices and methods thatinclude a rotatable blade attached to the end of a tube.

FIGS. 35A-C provides examples of termination devices and methods thatinclude a hook that pulls excess tether over a cutting surface to severthe tether.

FIGS. 36A-B show examples of termination devices and methods thatinclude the use of angled barbs to cut excess tether.

FIG. 37 illustrates variations of termination devices and methods inwhich a cutter attached to an expandable member is used to cut a tether.

FIGS. 38A-D show examples of various termination devices and methodsthat involve threading a tether between pins and severing the section oftether extended between the pins.

FIG. 39 shows one variation of a termination device as described herein.

FIGS. 40A and 40B show different variations of termination devices.

FIG. 41A shows a termination device and a loading device for loading atether into a termination device.

FIG. 41B shows a termination device with a detachable locking feature.

FIG. 41C shows the locking feature of FIG. 41B after detaching from therest of the termination device.

FIGS. 42A and 42B show one variation of a termination device.

DETAILED DESCRIPTION

The present application discloses methods and devices for tighteningtissue. These methods generally involve securing to the tissue a firstanchor that is coupled to a tether, securing to the tissue a secondanchor that is slidably coupled to the tether, applying tension to thetether, fixing the position of the tether with respect to the secondanchor, and cutting the tether. Any or all of these steps can beperformed intravascularly. For example, tension can be applied to thetether intravascularly, and the anchors can be secured to the tissueintravascularly. Although for exemplary purposes the followingdescription typically focuses on uses of the disclosed methods anddevices in mitral valve and other heart valve repair, such descriptionshould not be interpreted to limit the scope of the invention as definedby the claims. Tissue tightened by the disclosed methods and devices maycomprise any part of the body including, for example, the heart,bladder, stomach, gastroesophageal junction, vasculature, gall bladder,or the like. The methods and devices disclosed herein may be used, forexample, to close or reduce the diameter of any suitable body lumen,valve or structure or to tether portions of tissue which are separate orwhich have been traumatically severed.

Heart tissue tightened by the disclosed methods and devices maycomprise, for example, an atrial-septal defect or a heart valve annulussuch as, for example, a mitral valve annulus. In many cases, methodsdisclosed herein may be performed on a beating heart. Access to thebeating heart may be accomplished by any available technique, includingintravascular, transthoracic, and the like. In addition to beating heartaccess, the methods disclosed herein may be used for intravascularstopped heart access as well as stopped heart open chest procedures.

The first portion of this application will describe exemplary methodsand devices for securing tethered anchors to tissue in the context of aheart valve repair procedure. The anchors can be secured to tissueintravascularly. Subsequent portions of the application will describeexemplary methods and devices for applying tension to the tether totighten the tissue, for locking the tether to an anchor or otherwisefixing the position of the tether with respect to an anchor to maintainthe tension, and for cutting the tether. The methods and devicesdescribed for performing these steps are meant to be exemplary andshould not be interpreted as limiting the scope of the claims.

Referring now to FIG. 1, a heart H is shown in cross section, with anelongate anchor delivery device 100 introduced within the heart H.Generally, delivery device 100 comprises an elongate body with a distalportion 102 configured to deliver anchors to, for example, a heart valveannulus. (In FIGS. 1, 2A and 2B, distal portion 102 is showndiagrammatically without anchors or an anchor-delivery mechanism toenhance clarity of the figures.) In some embodiments, the elongate bodycomprises a rigid shaft, while in other embodiments it comprises aflexible catheter, so that distal portion 102 may be positioned in theheart H and, for example, under one or more valve leaflets to engage avalve annulus via a intravascular approach. Intravascular access may begained, for example, through the internal jugular vein (not shown) tothe superior vena cava SVC to the right atrium RA, across theinteratrial septum to the left atrium LA, and then under one or moremitral valve leaflets MVL to a position within the left ventricle (LV)under the valve annulus (not shown). Alternatively, access to the heartmay be achieved via the femoral vein and the inferior vena cava. Inother embodiments, access may be gained via the coronary sinus (notshown) and through the atrial wall into the left atrium. In still otherembodiments, access may be achieved via a femoral artery and the aorta,into the left ventricle, and under the mitral valve. Any other suitableaccess route may also be used.

In other embodiments, access to the heart H may be transthoracic, withdelivery device 100 being introduced into the heart via an incision orport in the heart wall. Even open heart surgical procedures may benefitfrom the disclosed methods and devices. Furthermore, some embodimentsmay be used to enhance procedures on the tricuspid valve annulus,adjacent the tricuspid valve leaflets TVL, or any other cardiac orvascular valve. Therefore, although the following description typicallyfocuses on minimally invasive or less invasive mitral valve repair fortreating mitral regurgitation, the disclosed methods and devices are inno way limited to that use.

With reference now to FIGS. 2A and 2B, a method for positioning deliverydevice 100 for treating a mitral valve annulus VA is depicteddiagrammatically in a cross-sectional view. First, as in FIG. 2A, distalportion 102 is positioned in a desired location under a mitral valveleaflet L and adjacent a ventricular wall VW. (Again, distal portion 102is shown without anchors or anchor-delivery mechanism for demonstrativepurposes.) The valve annulus VA generally comprises an area of heartwall tissue at the junction of the ventricular wall VW and the atrialwall AW that is relatively fibrous and, thus, significantly strongerthan leaflet tissue and other heart wall tissue.

Distal portion 102 may be advanced into position under the valve annulusby any suitable technique, some of which are described below in furtherdetail. Generally, distal portion 102 may be used to deliver and secureanchors to the valve annulus, to stabilize and/or expose the annulus, orboth. In some embodiments using a delivery device having a flexibleelongate body as shown in FIG. 1, a flexible distal portion 102 may bepassed from the right atrium RA through the interatrial septum in thearea of the foramen ovale (not shown—behind the aorta A), into the leftatrium LA and thus the left ventricle LV. Alternatively, flexible distalportion 102 may be advanced through the aorta A and into the leftventricle LV, for example using access through a femoral artery.Oftentimes, distal portion 102 will then naturally travel, upon furtheradvancement, under the posterior valve leaflet L into a space definedabove a subvalvular space 104 roughly defined for the purposes of thisapplication as a space bordered by the inner surface of the leftventricular wall VW, the inferior surface of mitral valve leaflets L,and cordae tendineae CT connected to the ventricular wall VW and theleaflet L. It has been found that a flexible anchor delivery catheter,such as the delivery devices disclosed herein, when passed under themitral valve via an intravascular approach, often enters subvalvularspace 104 relatively easily and may be advanced along space 104 eitherpartially or completely around the circumference of the valve. Once inspace 104, distal portion 102 may be conveniently positioned at theintersection of the valve leaflet(s) and the ventricular wall VW, whichintersection is immediately adjacent or very near to the valve annulusVA, as shown in FIG. 2A. These are but examples of possible accessroutes of an anchor delivery device to a valve annulus, and any otheraccess routes may be used.

In some embodiments, distal portion 102 includes a shape-changingportion which enables distal portion 102 to conform to the shape of thevalve annulus VA. The catheter may be introduced through the vasculaturewith the shape-changing distal portion in a generally straight, flexibleconfiguration. Once it is in place beneath the leaflet at theintersection between the leaflet and the interior ventricular wall, theshape of distal portion 102 is changed to conform to the annulus andusually the shape is “locked” to provide sufficient stiffness orrigidity to permit the application of force from distal portion 102 tothe annulus. Shaping and optionally locking distal portion 102 may beaccomplished in any of a number of ways. For example, in someembodiments, a shape-changing portion may be sectioned, notched, slottedor segmented and one or more tensioning members such as tensioningcords, wires or other tensioning devices coupled with the shape-changingportion may be used to shape and rigidify distal portion 102. Asegmented distal portion, for example, may include multiple segmentscoupled with two tensioning members, each providing a differentdirection of articulation to the distal portion. A first bend may becreated by tensioning a first member to give the distal portion aC-shape or similar shape to conform to the valve annulus, while a secondbend may be created by tensioning a second member to articulate theC-shaped member upwards against the annulus. In other embodiments, ashaped expandable member, such as a balloon, may be coupled with distalportion 102 to provide for shape changing/deforming. In variousembodiments, any configuration and combination may be used to givedistal portion 102 a desired shape.

For transthoracic methods and other embodiments, distal portion 102 maybe pre-shaped, and the method may simply involve introducing distalportion 102 under the valve leaflets. The pre-shaped distal portion 102may be rigid or formed from any suitable super-elastic or shape memorymaterial, such as nickel titanium alloys, spring stainless steel, or thelike.

In addition to delivering and securing anchors to the valve annulus VA,delivery device 100 (and specifically distal portion 102) may be used tostabilize and/or expose the valve annulus VA. Such stabilization andexposure procedures are described fully in U.S. patent application Ser.No. 10/656,797, which was previously incorporated by reference. Forexample, once distal portion 102 is positioned under the annulus, forcemay be applied to distal portion 102 to stabilize the valve annulus VA,as shown in FIG. 2B. Such force may be directed in any suitabledirection to expose, position and/or stabilize the annulus. For example,upward and lateral force is shown in FIG. 2B by the solid-headed arrowdrawn from the center of distal portion 102. In other cases, onlyupward, only lateral, or any other suitable force(s) may be applied.With application of force to distal portion 102, the valve annulus VA iscaused to rise or project outwardly, thus exposing the annulus foreasier viewing and access. The applied force may also stabilize thevalve annulus VA, also facilitating surgical procedures andvisualization.

Some embodiments may include a stabilization component as well as ananchor delivery component. For example, some embodiments may include twoflexible members, one for contacting the atrial side of a valve annulusand the other for contacting the ventricular side. In some embodiments,such flexible members may be used to “clamp” the annulus between them.One of such members may be an anchor delivery member and the other maybe a stabilization member, for example. Any combination andconfiguration of stabilization and/or anchor delivery members iscontemplated.

Referring now to FIGS. 2C and 2D, an anchor delivery device 108 is showndelivering and securing an anchor 110 to a valve annulus VA. These areagain representational figures and are not drawn to scale. Anchor 110 isshown first housed within delivery device 108 (FIG. 2C) and thendelivered to the annulus VA (FIG. 2D). As is shown, in some embodimentsanchors 110 may have a relatively straight configuration when housed indelivery device 108, for example, anchors 110 may have two sharpenedtips (although they need not be) and a loop in between the tips. Upondeployment from delivery device 108, the tips of anchor 110 may curve inopposite directions to form two semi-circles, circles, ovals,overlapping helices or the like. This is but one example of a type ofself-securing anchor that may be delivered to a valve annulus.Typically, multiple coupled anchors 110 are delivered, and the anchors110 are drawn together to tighten the valve annulus. Methods for anchordelivery and for drawing anchors together are described further below.

Although delivery device 108 is shown having a circular cross-sectionalshape in FIGS. 2C and 2D, it may alternatively have any other suitableshape. In some embodiments, for example, it may be advantageous toprovide a delivery device having an ovoid or elliptical cross-sectionalshape. Such a shape may help ensure that the device is aligned, whenpositioned in a corner formed by a ventricular wall and a valve leaflet,such that one or more openings in the delivery device is oriented todeliver the anchors into valve annulus tissue. To further enhancecontacting of the valve annulus and/or orientation of the deliverydevice, some embodiments may further include an expandable member,coupled with the delivery device, which expands to urge or press orwedge the delivery device into the corner formed by the ventricle walland the leaflet to contact the valve annulus. Such enhancements aredescribed further below.

With reference now to FIG. 3, some embodiments of a portion of an anchordelivery device 200 suitably include an elongate shaft 204 having adistal portion 202 configured to deliver a plurality of anchors 210,coupled with a tether 212, to tissue of a valve annulus. Tetheredanchors 210 are housed within a housing 206 of distal portion 202, alongwith one or more anchor retaining mandrels 214 and an expandable member208. Many variations may be made to one or more of these features, andvarious parts may be added or eliminated. Some of these variations aredescribed further below, but no specific embodiment(s) should beconstrued to limit the scope of the invention as defined by the appendedclaims.

Housing 206 may be flexible or rigid in various embodiments. In someembodiments, for example, flexible housing 206 may be comprised ofmultiple segments configured such that housing 206 is deformable bytensioning a tensioning member coupled to the segments. In someembodiments, housing 206 is formed from an elastic material having ageometry selected to engage and optionally shape or constrict the valveannulus. For example, the rings may be formed from super-elasticmaterial, shape memory alloy such as nickel titanium alloys, springstainless steel, or the like. In other instances, housing 206 could beformed from an inflatable or other structure that can be selectivelyrigidified in situ, such as a gooseneck or lockable element shaft, anyof the rigidifying structures described above, or any other rigidifyingstructure.

“Anchors,” for the purposes of this application, is defined to mean anyfasteners. Thus, anchors (e.g., anchors 210) may comprise C-shaped orsemicircular hooks, curved hooks of other shapes, straight hooks, barbedhooks, clips of any kind, T-tags, or any other suitable fastener(s). Insome embodiments, as described above, anchors may comprise two tips thatcurve in opposite directions upon deployment, forming two intersectingsemi-circles, circles, ovals, helices or the like. In some embodiments,anchors (e.g., anchors 210) are self-deforming. By “self-deforming” itis meant that anchors change from a first undeployed shape to a seconddeployed shape upon release of anchors from restraint in a housing(e.g., release of anchors 210 from housing 206). Such self-deforminganchors may change shape as they are released from a housing and entervalve annulus tissue to secure themselves to the tissue. Thus, for theexample shown in FIG. 3, a crimping device or other similar mechanism isnot required on distal end 202 to apply force to anchors 210 to attachthem to annular tissue. Self-deforming anchors may be made of anysuitable material, such as a super-elastic or shape-memory material likea nickel titanium alloy or spring stainless steel. In other embodiments,anchors may be made of a non-shape-memory material and may be loadedinto a housing in such a way that they change shape upon release.Alternatively, anchors that are not self-deforming may be used, and suchanchors may be secured to tissue via crimping, firing or the like. Evenself-securing anchors may be crimped in some embodiments to provideenhanced attachment to tissue. Delivery of anchors may be accomplishedby any suitable device and technique, such as by simply releasing theanchors by hydraulic balloon delivery as discussed further below. Anynumber, size and shape of anchors may be included in a housing.

In some embodiments, anchors (e.g., anchors 210) are generally C-shapedor semicircular in their undeployed form, with the ends of the “C” beingsharpened to penetrate tissue or being blunt, but configured topenetrate tissue when expanded with force. Approximately midway alongthe C-shaped anchor, an eyelet may be formed for allowing slidablepassage of a tether (e.g., tether 212). To maintain anchors 210 in theirC-shaped, undeployed state, anchors 210 may be retained within housing206 by two mandrels 214, one mandrel 214 retaining each of the two armsof the C-shape of each anchor 210. Mandrels 214 may be retractablewithin elongate catheter body 204 to release anchors 210 and allow themto change from their undeployed C-shape to a deployed shape. Thedeployed shape, for example, may approximate a complete circle or acircle with overlapping ends, the latter appearing similar to a keyring. Such anchors are described further below, but generally may beadvantageous in their ability to secure themselves to annular tissue bychanging from their undeployed to their deployed shape. In someembodiments, anchors (e.g., anchors 210) are also configured to lieflush with a tissue surface after being deployed. By “flush” it is meantthat no significant amount of an anchor protrudes from the surface,although some small portion may protrude.

Tethers (e.g., tether 212) may be one long piece of material or two ormore pieces and may comprise any suitable material, such as suture,suture-like material, a DACRON® polyester strip or the like. Retainingmandrels 214 may also have any suitable configuration and be made of anysuitable material, such as stainless steel, titanium, nickel titaniumalloys, or the like. Various embodiments may have one mandrel, twomandrels, or more than two mandrels.

In some embodiments, anchors 210 may be released from mandrels 214 tocontact and secure themselves to annular tissue without any furtherforce applied by delivery device 200. Some embodiments, however, mayalso include one or more expandable members 208, which may be expandedto help drive anchors 210 into tissue. Expandable member(s) 208 may haveany suitable size and configuration and may be made of any suitablematerial(s). Hydraulic systems such as expandable members are known inthe art, and any known or as yet undiscovered expandable member may beincluded in housing 206 as part of the present invention.

Referring now to FIGS. 4 and 5, a segment of a distal portion 302 of ananchor delivery device suitably includes a housing 306, multipletensioning members 320 for applying tension to housing 306 to change itsshape, two anchor retaining mandrels 314 slidably disposed in housing306, multiple anchors 310 slidably coupled with a tether 312, and anexpandable member 308 disposed between anchors 310 and housing 306. Ascan be seen in FIGS. 4 and 5, housing 306 may include multiple segmentsto allow the overall shape of housing 306 to be changed by applyingtension to tensioning members 320. As also is evident from the drawings,“C-shaped” anchors 310 may actually have an almost straightconfiguration when retained by mandrels 314 in housing 306. Thus, forthe purposes of this application, “C-shaped” or “semicircular” refers toa very broad range of shapes including a portion of a circle, a slightlycurved line, a slightly curved line with an eyelet at one point alongthe line, and the like.

With reference now to FIG. 6, the same segment of distal portion 302 isshown, but mandrels 314 have been withdrawn from two mandrel apertures322, to release anchors 310 from housing 306. Additionally, expandablemember 308 has been expanded to drive anchors out of housing 306.Anchors 310, having been released from mandrels 314, have begun tochange from their undeployed, retained shape to their deployed, releasedshape.

Referring now to FIGS. 7A-7E, a cross-section of a distal portion 402 ofan anchor delivery device is shown in various stages of delivering ananchor to tissue of a valve annulus VA. In FIG. 7A, distal portion 402is positioned against the valve annulus, an anchor 410 is retained bytwo mandrels 414, a tether 412 is slidably disposed through an eyelet onanchor 410, and an expandable member 408 is coupled with housing 406 ina position to drive anchor 410 out of housing 406. When retained bymandrels 414, anchor 410 is in its undeployed shape. As discussed above,mandrels 414 may be slidably retracted, as designated by thesolid-tipped arrows in FIG. 7A, to release anchor 410. In variousembodiments, anchors 410 may be released one at a time, such as byretracting mandrels 414 slowly, may be released in groups, or may all bereleased simultaneously, such as by rapid retraction of mandrels 414.

In FIG. 7B, anchor 410 has begun to change from its undeployed shape toits deployed shape (as demonstrated by the hollow-tipped arrows) and hasalso begun to penetrate the annular tissue VA. Empty mandrel apertures422 demonstrate that mandrels 414 have been retracted at least farenough to release anchor 410. In FIG. 7B, expandable member 408 has beenexpanded to drive anchor 410 partially out of housing 406 and furtherinto the valve annulus VA. Anchor 410 also continues to move from itsundeployed towards its deployed shape, as shown by the hollow-tippedarrows. In FIG. 7D, anchor 410 has reached its deployed shape, which isroughly a completed circle with overlapping ends or a “key ring” shape.In FIG. 7E, delivery device 402 has been removed, leaving a tetheredanchor secured in place in the valve annulus. Of course, there willtypically be a plurality of tethered anchors secured to the annulartissue. Tether 412 may then be cinched to apply force to anchors 410 andcinch and tighten the valve annulus. The tether may be cinched using anysuitable device or method. For example, during cinching a force can beapplied to the most proximal anchor having a vector component counter tothe force applied to the tether to cinch the tether. An intravasculardevice, such as a pusher, may be used to apply this force to the mostproximal anchor.

With reference now to FIGS. 8A and 8B, a diagrammatic representation ofanother embodiment of coupled anchors is shown. Here, anchors 510 arecoupled to a self-deforming or deformable coupling member or backbone505. Backbone 505 may be fabricated, for example, from nickel titaniumalloys, spring stainless steel, or the like, and may have any suitablesize or configuration. In one embodiment, as in FIG. 8A, backbone 505 isshaped as a generally straight line when held in an undeployed state,such as when restrained within a housing of an anchor deliver device.When released from the delivery device, backbone 505 may change to adeployed shape having multiple bends, as shown in FIG. 8B. By bending,backbone 505 shortens the longitudinal distance between anchors, asdemonstrated by the solid-tipped arrows in FIG. 8B. This shorteningprocess may act to cinch a valve annulus into which anchors 510 havebeen secured. Thus, anchors 510 coupled to backbone 505 may be used tocinch a valve annulus without using a tether or applying tetheringforce. Alternatively, a tether may also be coupled with anchors 510 tofurther cinch the annulus. In such an embodiment, backbone 505 will beat least partially conformable or cinchable, such that when force isapplied to anchors 510 and backbone 505 via a tether, backbone 505 bendsfurther to allow further cinching of the annulus.

Referring now to FIGS. 9A-9C, in some embodiments a flexible distalportion of an anchor delivery device 520 suitably includes a housing 522coupled with an expandable member 524. Housing 522 may be configured tohouse multiple coupled anchors 526 and an anchor contacting member 530coupled with a pull cord 532. Housing 522 may also include multipleapertures 528 for allowing egress of anchors 526. For clarity, deliverydevice 520 is shown without a tether in FIGS. 9A and 9C, but FIG. 9Bshows that a tether 534 may extend through an eyelet, loop or otherportion of each anchor 526, and may exit each aperture 528 to allow forrelease of the plurality of anchors 526. Various features of theseembodiments are described further below.

In the embodiments shown in FIGS. 9A-9C, anchors 526 are relativelystraight and lie relatively in parallel with the long axis of deliverydevice 522. Anchor contacting member 530, which may comprise anysuitable device, such as a ball, plate, hook, knot, plunger, piston, orthe like, generally has an outer diameter that is nearly equal to orslightly less than the inner diameter of housing 522. Contacting member530 is disposed within the housing, distal to a distal-most anchor 526,and is retracted relative to housing 522 by pulling pull cord 532. Whenretracted, anchor contacting member 530 contacts and applies force to adistal-most anchor 526 to cause that anchor 526 to exit housing 522 viaone of the apertures 528. Contacting member 530 is then pulled fartherproximally to contact and apply force to the next anchor 526 to deploythat anchor 526, and so on.

Retracting contacting member 530 to push anchors 526 out of apertures528 may help cause anchors 526 to avidly secure themselves to adjacenttissue. Using anchors 526 that are relatively straight/flat whenundeployed allows anchors 526 with relatively large deployed sizes to bedisposed in and delivered from a relatively small housing 522. In someembodiments, for example, anchors 526 that deploy into a shapeapproximating two intersecting semi-circles, circles, ovals, helices, orthe like, and that have a radius of one of the semi-circles of about 3mm may be disposed within a housing 522 having a diameter of about 5French (1.67 mm), or about 4 French (1.35 mm), or even smaller. Suchanchors 526 may measure about 6 mm or more in their widest dimension.These are only examples, however, and other larger or smaller anchors526 may be disposed within a larger or smaller housing 522. Furthermore,any convenient number of anchors 526 may be disposed within housing 522.In some embodiments, for example, housing 522 may hold about 1-20anchors 526, or about 3-10 anchors 526. Other embodiments may hold moreanchors 526.

Anchor contacting member 530 and pull cord 532 may have any suitableconfiguration and may be manufactured from any material or combinationof materials. In alternative embodiments, contacting member 530 may bepushed by a pusher member to contact and deploy anchors 526.Alternatively, any of the anchor deployment devices and methodspreviously described may be used.

Tether 534, as shown in FIG. 9B, may comprise any of the tethers 534 ortether-like devices already described above, or any other suitabledevice. Tether 534 is generally fixedly coupled to a distal-most anchor526 at an attachment point 536. By “fixedly coupled,” here it is meantthat tether 534 is coupled to distal-most anchor 526 in a manner thatprevents tether 534 from sliding through or past distal-most anchor 526in the direction of more proximal neighboring anchors 526. This may beachieved, for example, via a knot, weld, adhesive, or by any othersuitable mechanism that fixedly couples tether 534 to distal-most anchor526. Fixedly coupling includes, for example, via a knot, protuberance,or other feature on tether 534 that cannot pass through an eyelet, loop,or other similar feature in distal-most anchor 526 through which tether534 passes. Tether 534 then extends through an eyelet, loop or othersimilar feature on each of the anchors 526 so as to be slidably coupledwith the anchors 526. In the embodiments shown, tether 534 exits eachaperture 528, then enters the next-most-proximal aperture, passesslidably through a loop on an anchor 526, and exits the same aperture528. By entering and exiting each aperture 528, tether 534 allows theplurality of anchors 526 to be deployed into tissue and cinched. Otherconfigurations of housing 522, anchors 526 and tether 534 mayalternatively be used. For example, housing 522 may include alongitudinal slit through which tether 534 may pass, thus allowingtether 534 to reside wholly within housing before deployment.

Expandable member 524 is an optional feature of anchor delivery device520, and thus may be included in some embodiments and not in others. Inother words, a distal portion of anchor delivery device 520 may includehousing, contents of housing, and other features either with or withoutan attached expandable member. Expandable member 524 may comprise anysuitable expandable member currently known or discovered in the future,and any method and substance(s) may be used to expand expandable member524. Typically, expandable member 524 will be coupled with a surface ofhousing 522, will have a larger expanded radius than housing 522, andwill be configured such that when it is expanded as housing 522 nears orcontacts the valve annulus, expandable member 524 will push or presshousing 522 into enhanced contact with the annulus. For example,expandable member 524 may be configured to expand within a space nearthe corner formed by a left ventricular wall and a mitral valve leaflet.

Generally, anchor delivery device 520 may be advanced into any suitablelocation for treating any valve by any suitable advancing or deviceplacement method. Many catheter-based, minimally invasive devices andmethods for performing intravascular procedures, for example, are wellknown, and any such devices and methods, as well as any other devices ormethod described in this application or later developed, may be used toadvance or position delivery device 520 in a desired location.

Another implementation of a method for securing a plurality of tetheredanchors 526 to a mitral valve annulus VA in a heart is now describedwith reference to FIGS. 10A-10F, 11, and 12A-12F. Referring first toFIG. 11 (a cross-sectional depiction of a heart H), in one embodiment afirst guide catheter 550 is advanced in retrograde fashion through theaorta A, typically via access from a femoral artery. Guide catheter 550is passed into the left ventricle LV of the heart and thus into thesubannular space 552. Subannular space 552 is generally defined by theleft ventrical wall, the mitral valve leaflets MVL, and cordae tendineaeof the left ventricle and travels along most or all of the circumferenceof the valve annulus. Guide catheter 550 is generally a flexibleelongate catheter which may have one or more curves or bends toward itsdistal end to facilitate placement of the distal end of catheter 550 insubannular space 552. The distal end of guide catheter 550 may beconfigured to be positioned at an opening into or within subannularspace 552 such that subsequent catheter devices may be passed throughguide catheter 550 into space 552.

In FIGS. 12A-12F the mitral valve MV, including mitral valve leafletsMVL, is represented diagrammatically from an inferior perspectivelooking up. In FIG. 12A, guide catheter 550 is show extending up to orinto subannular space 552, as in FIG. 11. As shown in FIG. 12B, a secondguide catheter 554 may be advanced through first guide catheter 550 topass through/along a portion or all of subannular space 552. In oneembodiment this second guide catheter 554 is steerable (as describedbelow with respect to FIGS. 13A and 13B, for example), to help conformsecond guide catheter 554 to subannular space 552.

Next, as shown in FIG. 12C, a guide sheath 556 may be passed over secondguide catheter 554 to extend along subannular space 552. Sheath 556 isgenerally a flexible, tubular member that can be passed over secondguide catheter 554 and within first guide catheter 550. To enhancepassage and exchange, any of these and other described catheter members,sheath members, or the like may be manufactured from and/or coated withone or more friction resistant materials. Once sheath 556 is in place,second guide catheter 554 may be withdrawn, as shown in FIG. 12D. Asshown in FIG. 12E, an anchor delivery device 520 (described above) maythen be advanced through sheath 556 to a desired position withinsubannular space 552. Sheath 556 may then be withdrawn, as in FIG. 12F,leaving anchor delivery device 520.

These are only exemplary methods for advancing an anchor delivery deviceto a position for treating a valve annulus, and any other suitablemethod or combination of devices may be used to position an anchordelivery device. In various alternative embodiments, one or more stepsmay be added, deleted or modified while achieving a similar result. Insome embodiments, a similar method may be used to treat the mitral valvefrom a superior/right atrial position or to treat another heart valve.Additionally, other devices or modifications of the systems justdescribed may be used in other embodiments.

Referring now to FIG. 10A, anchor delivery device 520 is contacted withthe valve annulus VA such that openings 528 are oriented to deployanchors 526 into the annulus. Such orientation may be achieved by anysuitable technique. In some embodiments, for example, a housing 522having an elliptical cross-sectional shape may be used to orientopenings 528. As described above, in some implementations contactbetween housing 522 and the valve annulus VA may be enhanced byexpanding an expandable member 524 to wedge housing 522 within thecorner formed by the left ventricular wall and the valve leaflets.

As shown in FIG. 10B, when delivery device 520 is positioned in adesired location for deploying anchors 526, anchor contacting member 530is retracted to contact and apply force to a most-distal anchor 526 tobegin deploying anchor 526 through aperture 528 and into tissue of thevalve annulus VA. FIG. 10C shows anchor 526 further deployed out ofaperture 528 and into valve annulus VA. FIG. 10D shows the valve annulusVA transparently so that further deployment of anchors 526 can be seen.As shown, in some embodiments anchors 526 include two sharpened tips(although they need not be) that move in opposite directions uponrelease from housing 522 and upon contacting the valve annulus VA.Between the two sharpened tips, an anchor 526 may be looped or have anyother suitable eyelet or other device for allowing slidable couplingwith a tether 534.

Referring now to FIG. 10E, anchors 526 are seen in their fully deployedor nearly fully deployed shape, with each tip (or “arm”) of each anchor526 having curved to form a circle or semi-circle. Of course, in variousembodiments anchors 526 may have any other suitable deployed andundeployed shapes, as described more fully above. FIG. 10F shows anchors526 deployed into and secured to the valve annulus VA and coupled withtether 534, with the distal-most anchor 526 fixedly coupled to tether534 at attachment point 536 and other anchors 526 slidably coupled totether 534.

Although the implementation just described employed anchor deliverydevice 520, any other suitable anchor delivery devices known, describedherein, or later developed may also be used to secure a plurality oftethered anchors to a mitral valve annulus or other tissue. In someimplementations, after the anchors have been secured to the tissue theanchor delivery device may be withdrawn. In other implementations, asdescribed below, the anchor delivery device may be further employed insubsequent steps of a tissue tightening method. In some embodiments, theanchor delivery device is withdrawn through first guide catheter 550,and first guide catheter 550 is then withdrawn. In alternativeembodiments, first guide catheter 550 may be withdrawn before the anchordelivery device is withdrawn.

In various embodiments, alternative methods may be used to urge ananchor delivery device into contact with the valve annulus. For example,in some embodiments a magnet may be coupled with the anchor deliverydevice, and another anchor may be disposed within the coronary sinus, inproximity to the first magnet. The two magnets may attract one another,thus pulling the anchor delivery device into greater contact with theannulus. Various embodiments may also include visualizing the annulususing a visualization member coupled with or separate from the anchordelivery device. In some embodiments, the tether is a strip ofdetachable, biocompatible material, such as DACRON® polyester, that iscoupled with the anchor delivery device. The anchors are driven throughthe strip, which detaches to affix to the valve annulus via the anchors.In other embodiments, the tether is a detachable, biocompatible, distalportion of the guide sheath through which the anchors are driven, andthat portion of the guide sheath remains attached to the annulus via theanchors.

Referring again to FIG. 10F, after the plurality of tethered anchors 526has been secured to the valve annulus, tension may be applied to tether534 to cinch tether 534 and thereby tighten the annulus, thus reducingvalve regurgitation. In some embodiments, valve function may bemonitored by any suitable method, such as echocardiogram and/orfluoroscopy, and tether 534 may be cinched, loosened, and adjusted toachieve a desired amount of tightening as evident via the employedvisualization technique(s) or monitored function(s). When a desiredamount of tightening is achieved, tether 534 is then fixedly coupled toa most-proximal anchor 526 (or to two or more most-proximal anchors526), using any suitable technique. By “fixedly coupled,” here it ismeant that tether 534 is coupled to most-proximal anchor or anchors 526in a manner that prevents tether 534 from sliding through or past mostproximal anchor or anchors 526 in the direction of more distal anchors526. Suitable techniques for fixedly coupling tether 534 to mostproximal anchor or anchors 536 include but are not limited to use ofadhesives, tying, knotting, crimping the anchor, deforming the anchor,clamping the tether to the anchor, and providing a locking feature onthe tether that, for example, cannot pass through an eyelet, loop, orother similar feature in the most proximal anchor or anchors. Some ofthese techniques are discussed in additional detail below.

Still referring to FIG. 10F, after tether 534 has been fixedly coupledto most proximal anchor or anchors 526, tether 534 is cut proximal tothe most-proximal anchor 526, thus leaving the cinched, tethered anchors526 in place along the valve annulus VA. Tether 534 may be cut via anytechnique such as, for example, with a cutting member coupled withhousing 522. Techniques and devices for cutting tether 534 are discussedin additional detail below.

In some embodiments it may be advantageous to deploy a first set ofanchors 526 along a first portion of a valve annulus VA, cinch the firstset of anchors to tighten that portion of the annulus, move the deliverydevice 520 to another portion of the annulus (typically the oppositeside), and deploy and cinch a second set of anchors 526 along a secondportion of the annulus. Such a method may be more convenient in somecases than extending delivery device 520 around all or most of thecircumference of the annulus, and may allow a shorter, more maneuverablehousing 522 to be used.

In some embodiments the steps of securing the anchors to the tissue,applying tension to the tether, fixedly coupling the tether to the mostproximal anchor or anchors and cutting the tether are performed by thesame device. Any or all of these steps may be performed intravascularly.In other embodiments different devices may be used to perform each stepor combinations of these steps. For example, in some embodiments, afirst device deploys and secures the anchors to tissue and one or moreother devices performs the termination steps of applying tension to thetether, fixedly coupling the tether to one or more of the most proximalanchors, and cutting the tether. Devices that perform one or more ofthese termination steps are described herein as termination devices.

If an initial step is performed by a first device and a subsequent stepis to be performed by a second device such as a termination device, itmay be necessary to load the tether into the second device. Both devicescan be intravascular devices. Generally such loading will occur afterthe tethered anchors have been secured to tissue. The tether may beloaded into the second device prior to introducing the second deviceinto the body, e.g., into the vasculature. Alternatively, the tether maybe loaded into the second device in situ (e.g., intravascularly).

Referring now to FIGS. 14A and 14B, in some embodiments, tether 534 isloaded into termination device 600 using a lasso 604 (e.g., a threadingdevice) which comprises a loop 606 at one end. One end of tether 534(not shown) is coupled to a plurality of anchors that have been securedto tissue by, for example, the methods and/or devices described herein.The other end of tether 534 is threaded through loop 606 of lasso 604.Lasso 604 may then be pulled along the axis of termination device 600(FIG. 14A) or, in alternative implementations, through a side hole 608in termination device 600 (FIG. 14B) to load tether 534 into terminationdevice 600. Termination device 600 may then perform one or moretermination steps. Lasso 604 may be made from, for example, conventionalmaterials such as wire, suture, cable, string, or a monofilament. Thelasso may comprise a loop (as show in FIGS. 14A and 14B), a hook, acoil, a tube, an elongate element with hole, or any other structure ormaterial that can “grab” the tether.

In other embodiments (e.g., FIGS. 15A-15H) the tether is loaded into atermination device by threading the tether through one or more featuresin a rod and then inserting the rod into the termination device. Theserods may be of a length that facilitates easy handling, if applicable,and sized to interface with the termination device. Preferably, the rodsare 60-150 cm. The rods may be composed of any material which willperform the function of handling the tether, including metal and plastic(e.g., nylon, PEBAX, PEEK, Fluoro polymer like PTFE, PET, orpolyethylene, polypropylene, or metal braided polymer). The features inthe rod may be, for example, holes, openings, indents, grooves, andslits. The rod may remain in the termination device or be subsequentlyremoved. In some implementations a knot may be tied at the proximal endof the tether to prevent the tether from slipping out of the rod. Insome implementations the rod has a passage from one end of the rod to afirst opening in a side of the rod and another passage from the otherend of the rod to a second opening in a side of the rod. The tether maybe threaded through these passages. In FIG. 15A, for example, rod 610comprises a tube 612 with side holes 614. Tether 534 is threaded throughone end of the tube, through the two side holes, and through the otherend of the tube. Rod 610 is then inserted into termination device 600(FIG. 15B).

In other implementations, (FIG. 15C), rod 616 comprises a C-shapedfeature 618 through which tether 534 may be threaded. Rod 616 is theninserted into a termination device similarly to the example shown inFIG. 15B. Feature 618 may be, for example, a C-shaped fastener thatsnaps around tether 534. In these implementations, tether 534 maycomprise a knot or other suitable feature 620 that cannot pass throughC-shaped feature 618, thus improving the ability of rod 616 to pulltether 534 into a termination device.

In the implementations shown in FIGS. 15D-15F, rod 622 comprisesthrough—holes 624 oriented approximately perpendicular to a long axis ofthe rod and flat portions 626 and 628 oriented approximately parallel tothe long axis of the rod. Tether 534 runs along flats 626 and 628 whenit is threaded through holes 624. This configuration allows rod 622 andtether 534 to remain within a round profile. In the implementation shownin FIGS. 15G and 15H, rod 630 comprises holes 632 oriented approximatelyperpendicular to a long axis of the rod and grooves 634 orientedapproximately parallel to the long axis. Tether 534 runs along grooves634 when threaded through holes 632. In these implementations also, therod and tether may remain within a round profile. Other orientations ofholes, flats, and grooves may also be suitable in these implementations.

After a plurality of tethered anchors have been secured to tissue, insome embodiments the device used to deploy and secure the anchors may beused to apply tension to the tether to tighten the tissue. In otherembodiments, a termination device into which the tether has been loadedmay be used to apply the tension. In some embodiments, the deployment ortermination device is advanced along the tether to a location at or nearthe proximal end of the tethered anchors. The device may then be used toapply an opposing force to the most proximal anchor while tension isapplied to the tether to cinch it. The opposing force has a componentcounter to the tensioning force applied to the tether, and thusstabilizes the most proximal anchor as the tether is cinched. Theopposing force may be applied, for example, by contacting the mostproximal anchor with the deployment or termination device. Thedeployment or termination device may be an intravascular device.

During a tissue tightening procedure, e.g., an annuloplasty procedure, alocking or fixing feature should be applied to the cinching tether tofix its length so that tension is maintained. If anchors are beingsecured to the tissue, and the cinching tether is threaded through theanchors to tighten the tissue via the anchors, the end of the cinchingtether should not slide through an eye of the most proximal anchor.

Various fixing or locking features and methods can be used to fix theend of the cinching tether so that it does not slip through the mostproximal anchor. These features and methods can be used intravascularly.Several types of locking features can be used. These locking featuresgenerally fall into three categories: features that cannot slide;features that can slide until they hit a stop; and features that aredesigned to slide somewhat before locking, relieving some tension in thetether. For the latter type of features, an extra length of tether isprovided to accommodate the slippage. The locking features can beapplied to the most proximal anchor itself, or they can be applied tothe tether. In addition, the tether can be fixedly coupled to the mostproximal anchor by deforming the second anchor, e.g., by use of a devicethat can bend or twist the second anchor.

Knots can be used as locking features for tethers. One type of knot thatcan be used is a slip knot positioned near the most proximal anchor, asillustrated in FIG. 16A. Tether 534 is cinched until the tissue shape(e.g., valve tissue) is as desired. The proximal end of the tether isthreaded through a loop 710 of a tie 711 having slip knot 712. The loop710 is slid over tether 534 in a distal direction until it reaches or isclose to the most proximal anchor. Tie 711 is pulled to slide through713 to tighten the knot around tether 534 such that the tether is lockedin place and will not slip past the most proximal anchor, e.g., throughan eye of the most proximal anchor. Many different types of slip knotsmay be used, including Roeder's knots. In some variations, a secondaryslip knot can be applied to the end, slipping portion and/ornon-slipping portion of tie 711 to further lock knot 712 in place. Tie711 can be passed inside a catheter 713. In another variation, tether534 and tie 711 are joined with knots, including half knots, to furtherlock knot 712 in place.

In other variations, as shown in FIG. 16B, tether 534 can be loopedthrough anchors 526, with a slip knot 715 positioned near most proximalanchor closing the loop. Tether 534 can be looped through the eye ofmost distal anchor and then threaded through other anchors in anysuitable fashion that allows tension on the tether 534 to be adjusted asnecessary. For example, as illustrated in FIG. 16B, tether 534 can belooped through most distal anchor, then both strands can be threadedthrough the remaining anchors, except for the most proximal anchor. Onthe most proximal anchor, just one of the strands may be threadedthrough, while the other strands goes around the last anchor. Thus, theanchor forces the two strands of the knot to exit at angles relative toone another so that when tension is exerted on those strands, a knotsuch as the Roeder's knot self tightens. Slip knot 715 can be pushed tocinch tether 534 as desired and lock tether 534 into place. A knotpusher can be used to simultaneously cinch and push the knot. As theknot is pushed, tether 534 adjusts, sliding through the most distalanchor such that two sides of the loop of tether 534 are approximatelyequal in length. The force of tissue expanding outward can cause knot715 to tighten further. For the most distal anchor, tether 534 can bethreaded through a guided feed (not shown), such as a slotted devicecoupled to most distal anchor, to lessen friction as the tether 534 iscinched. A secondary tie having a secondary slip knot, for example,similar to tie 711 as shown in FIG. 16A, can be applied to tether 534 tohelp tighten knot 715. In addition, two knots (not shown) can be usedfor the variation shown in FIG. 16B. The tether can include a loophaving a first slip knot positioned proximal the most proximal anchorand a second slip knot positioned distal the most distal anchor. The twoslip knots positioned at opposite ends of the plurality of tetheredanchors can be used to adjust the length and tension in the loop of thetether.

In other variations illustrated in FIG. 16C, tether 534 can be threadedthrough all anchors 526 except the most proximal anchor 626. At thedistal end of tether 534 is a block 716, e.g., a knot or a washer or thelike, to prevent the most distal anchor from passing over the mostdistal end of tether 534. A second cinching cable 717 is threadedthrough only the most proximal anchor 626 and has block 718, e.g., aknot or a washer or the like, to prevent the most proximal anchor 626from passing over the most proximal end of cable 717. Cable 717 is usedto tie a slip knot 719 around tether 534 just proximal the second mostproximal anchor, such that knot 719 can slide along tether 534. Knot 719is pushed along tether 534 in a distal direction to cinch tether 534,e.g., by pusher 720. Expanding force of tissue can further tighten knot719.

In other variations as shown in FIG. 16D, a sliding half knot 721proximal of the most proximal anchor is passed distally down the lengthof tether 534 to the most proximal anchor. Half knot 721 is held open asit is slid distally down the length of tether 534. When half knot 721 isin the desired position, the device holding the knot open is released,and a pusher may push on the knot in a distal direction to tighten theknot. The knot can be held open by any suitable method. For example, asillustrated in FIG. 16E, pusher 727 can include a retractable member728, e.g., a wire form made from any suitable material such as a nickeltitanium alloy, that holds half knot 721 open. When half knot 721 ispositioned as desired to lock tether 534 in place, retractable member728 is retracted to release half knot 721. Alternatively, knot 721 canbe held open by sliding the knot around a round or elliptical roller(not shown) having a large enough cross-sectional diameter to preventthe knot from becoming tight and therefore not sliding. Knot 721 canalso be held open by placing pins (not shown) in the two loops of thehalf knot such that the loops, and therefore the knot, cannot tighten.In some variations knot 721 itself is large enough that it cannot passthrough the eye of most proximal anchor. In other variations, there is awasher or other blocking object 722 slidably coupled to tether 534 thatcannot pass through the eyelet of most proximal anchor. For any of thevariations including sliding a half knot, a mechanical feature thatholds the tether slack before, during, or after sliding the half knotcan be included. By holding the tether with sufficient slack, the knotgenerally will not tighten.

As shown in FIG. 16D, an additional cinching cable 723 having a knot orother impediment 724 on its distal end can be threaded through the mostproximal anchor so that the cinching cable 723 cannot pass through themost proximal anchor when pulled in a proximal direction. Half knot 721can then be tied with both cinching cable 723 and tether 534, creating abulkier knot. In some variations, both cinching cable 723 and tether 534are passed through washer or blocking object 722. In other variations,two tethers can be threaded through all anchors. The two tethers canthen used to make a half knot. Tube 727 can be pushed against half knot721 to push the knot in a distal direction to create a fully lockedknot, holding the tethers in place. Tube 727 can have a saddle (notshown) to aid in pushing. In some variations, the cinching tether ortethers can exit the side of pushing tube 727.

As shown in FIG. 17A, tether 734 can have protrusions 703 that allowtether 734 to slide through anchors 726, e.g., through anchor eyelets,in one direction, but not in the opposite direction. Protrusions 703 canbe arrow-shaped, V-shaped, cone-shaped, triangular, or have any othersuitable shape or geometry that allows them to pass in one directionthrough an opening but not in the reverse direction. Alternatively,protrusions 703 can comprise other shapes or objects, such as knots. Insome variations, as shown in FIG. 18A, the most proximal anchor 726′ hasan eyelet with a reduced cross-sectional dimension such that protrusions703 can pass as tether 734 is pulled in a proximal direction through theeyelet of anchor 726′, but not when tether 734 is pulled in a distaldirection. Tether 734 can be ratcheted into a desired tension assequential protrusions 703 are passed through the most proximal anchor726′. In other variations, as shown in FIG. 18B, a collar 705 ispositioned along tether 734 proximal to most proximal anchor 726′.Tether 734 is threaded through an opening 706 in collar 705. Opening 706can expand slightly such that protrusions 703 can pass through opening706 when they are pulled through in a proximal direction, but not whenpulled in a distal direction. For example, opening 706 can be agenerally fixed opening and protrusions 703 can be of such a shape as topass in the proximal direction through opening 706 but not in the distaldirection. Thus, as sequential protrusions 703 are passed throughopening 706, tether 734 is cinched tighter and locked into place.

Protrusions 703 can be of any type and provided by any suitable method.For example, tether 734 including protrusions 703 can be formed of sheetmetal, and then processed, e.g., by electropolishing or any othersuitable technique, to remove sharp corners and edges. Tether 734 andprotrusions 703 can also be formed of plastic, e.g., a plasticcomprising a TEFLON® fluoropolymer, or polyester. Alternatively,protrusions 703 can be added to tether 734 in a separate step, e.g., bythreading cones onto a suture and fixing the cones in place along thesuture at defined intervals. The cones can be bonded or otherwiseattached to or coupled with the suture.

Other methods for fixing the end of a tether such that tension ismaintained include threading the tether through a path having numeroustwists, turns, and or bends such that slippage of the tether isprevented.

A self-kinking tube can be used to clamp or lock a tensioned tether intoplace during termination. As shown in FIG. 19A, tube 870 that has beenpre-kinked along its length can be provided. A force can be applied totube 870 to compress it axially to maintain its kinked state, e.g., byproviding a spring extending between the ends of the tube. Asillustrated in FIG. 19B, a spring 871 having spring elements 872 can beprovided. Spring 871 can be placed in a collinear arrangement with tube870 such that ends of spring 871 are coupled to the ends of tube 870.Thus, spring 871 can assist in applying axial force to tube 870 tomaintain its kinked state. For example, spring 871 can be placed overtube 870, or alongside and generally parallel with tube 870. A secondstraight tube 873 (e.g., a catheter) can be provided which fits overspring 871 by compressing spring elements 872 inwardly (FIG. 19C). Thiscauses spring 871 to elongate, and therefore to elongate kinked tube 870into a generally straightened state (FIG. 19C). Tether 534 can bethreaded through straightened tube 870 such that tether 534 can moveback and forth through tube 870 freely. When it is desired to fix tether534 during termination, the force causing tube 870 to be at leastpartially unkinked can be released, allowing tube 870 to be restored toits kinked state to lock tether 534. For the examples illustrated inFIGS. 19A-C, second tube 873 can be removed from spring 871, thusallowing spring elements 872 to recover to their curved state, reducingthe length of spring 871, and causing tube 870 to recover to its kinkedstate. Once tube 870 is kinked, tether 734 can no longer freely move andis fixed into place. Tube 870 can be made of any material suitable foruse inside the human body and that can be transferred between astraightened and kinked state, such as nylon, PEBAX®, polyurethane,polyethylene terephthalate, polyethylene, polypropylene orpolyetheretherketone. Spring 871 can comprise any spring materialsuitable for use within the human body, such as stainless steel,titanium, or nickel titanium alloys or polyetheretherketone. Althoughspring 871 has been depicted as having a basket shape for purposes ofillustration, spring 871 can have any suitable shape.

The tether can be threaded through a clamp to lock it into place duringtermination. Clamping can involve applying a force to cause two surfaces(e.g., clamp jaws) of a locking feature together to clamp the tether.Clamping can also involve applying a force to separate two surfaces of alocking feature, passing the tether between the surfaces, and releasingthe force to clamp the tether between the surfaces. In some variations,the surfaces of the clamp jaws will be at least partially roughened,toothed, or made to have adhesive properties to hold the tether. Forexample, as illustrated in FIG. 20A, two sides of a clamp 880 can forman interlocking profile 882, e.g., a stepped profile or other profilehaving corners. Tether 534 is threaded through holes 881 such thattether 534 traverses profile 882 when clamp 880 is open. As clamp 880 isclosed, tether 534 is forced to follow the tortuous path imposed on itby the interlocking profile 882. Clamp 880 can be closed by any suitablemechanism, such as with a closure, or with a spring hinge. If clamp 880is closed by a spring hinge, it can be propped open using a proppingelement (not shown) while tether 534 is threaded through holes 881, andbefore it is desired to fix tether 534 into place. When it is desired tolock down tether 534 during termination, the propping element can beremoved. Alternatively, a spring hinge can have an open position,allowing tether 534 to slide freely through clamp 880. When it isdesired to fix the tether, the spring hinge can be snapped into a closedposition. Clamp 880 can have any suitable interior surfaces 883 suchthat when the clamp is closed, surfaces 883 prevent tether 534 fromslipping. In other embodiments, the clamp can have numerous structuralfeatures along its length. For example, as illustrated in FIG. 20B,clamp 1100 has a saw-toothed surface on inner surfaces of both jaws 1110and 1112 along its longitudinal axis, and tether 534 is threaded throughclamp 1100 along its longitudinal axis. Clamp jaws 1110 and 1112 can belocked together when it is desired to fix tether 534 upon termination byany suitable mechanism, such as by using a hinge or clamping mechanism.Besides the stepped surface illustrated in FIG. 20A and the saw-toothedsurface illustrated in FIG. 20B, other suitable clamping surfaces can beused, including roughened, notched, etched, scored, and the like.

FIG. 21A illustrates additional examples of toothed clamping devicesthat can be used to lock the tether during termination. In FIG. 21A,clamp 885 having first side 886 with protruding features 887 attachedthereto and second opposing side 888 with protruding features 889attached thereto is provided. Protruding features 887 and 889 are placedin an alternating manner along the long axis A-A′ of clamp 885 andextend into the interior volume of clamp 885 such that the only pathdown the long axis is tortuous when clamp 885 is closed. When clamp 885is opened (FIG. 21B), a generally unobstructed path down the long axisA-A′ of the interior of clamp 885 exists. Thus tether 534 can bethreaded through axis A-A′ of clamp 885 in its opened state. When clamp885 is closed (FIG. 21C), tether 534 will be forced in a tortuous pathby protrusions 887 and 889, and will thus be fixed into place. In somevariations, the rest state of clamp 885 is closed, and held open, e.g.,by a propping mechanism, to thread tether 534 through clamp 885 and toadjust tension on tether 534. When it is desired to lock tether 534,clamp 885 is allowed to close, e.g., by retracting the proppingmechanism. In other variations, the clamp is open during its rest stateso that tether 534 can easily slide through its interior. When it isdesired to fix tether 534, an external element clamps or deforms clamp885 such that it is in a closed state and protrusions 887 and 889 locktether 534.

The tether can be threaded through a coil or spring 890 in a directiongenerally orthogonal to the expandable direction of the spring.

Other clamping schemes can be used to lock a tether into place duringtermination. Several factors can influence how well a clamp holds atether. These include surface finish, surface area, elasticity ofmaterial, configuration of the tether in the clamp, and clamping force.For example, surfaces that are roughened, toothed, scored, etched,textured, or sticky (i.e., have adhesive properties) all increase theholding force of the clamp. In addition, a larger clamping surface areagenerally increases the holding force. In some cases, more elasticmaterials used for clamp jaws can provide increased hold on cinchingtethers. Designing a clamp so that it holds the cinching tether in abent, folded, curved, or other generally nonlinear configuration canincrease the holding force. A higher clamping force applied to thetether via clamp jaws increases the holding force of the clamp. All ofthese variables can be adjusted according to clamp design to providedesired features, e.g., size, cost, ease of use, installation method,and biocompatibility for area or type of use. Certain clamp features maybe desired for use with certain tether types or materials or diameters,for use with certain tension ranges, or for certain tissue types.Clamping devices can be used to clamp onto the tether such that thetether cannot move past the most proximal anchor. Alternatively,clamping devices can be used to clamp the tether to the most proximalanchor.

A clamping device, such as a clip, formed of a single piece of metal canbe provided to lock the tether during termination. An example of such aclamping device is illustrated in FIG. 22. For the embodiments shown inFIG. 22, clamp 910 is closed in its rest state. Before locking, tether534 is threaded through clamp 910, between propped-open jaws 911 and912. The jaws can be propped open by propping mechanism 913, e.g., awire, a tube, or any suitable mechanism. After the tether is in itsdesired position, the propping mechanism is withdrawn such that jaws 911and 912 clamp down on tether 534. The clamping device illustrated inFIG. 22 can be used either to clamp directly onto tether 534 or to clamptether 534 to most proximal anchor.

Clamping devices with expandable, deformable mesh may be used to clamptethers during termination. Examples of such clamping devices areillustrated in FIG. 23A-C. As shown in FIG. 23A, expandable member 901,e.g., a balloon, encased or partially encased in an expandable meshelement 902 is provided within tube 900, e.g., a catheter. Tether 534 isthreaded between inner wall 903 of tube 900 and outer wall 904 ofexpandable mesh element 902. As shown in FIG. 23B, as expandable member901 is expanded, tether 534 is compressed between mesh outer wall 904and tube inner wall 903. In some variations, it may be desired toprovide a mesh element having a textured surface, roughened surface, oradhesive properties to increase friction with tether 534. For example,as illustrated in FIG. 23C, mesh element 902 having flanges or otherprotruding features 905 can be provided that is capable of catchingand/or compressing tether 534. Mesh element 902 can be made of anysuitable material, e.g., metal, polymer, or any suitable type of fiber,and can have a tubular, or any other suitable, configuration. Tube 900can be made of any suitable material, and can be rigid or flexible. Forexample, tube 900 can include an elastomer. Inner wall 903 of tube 900can be coated with an elastomer or adhesive. The walls of tube 900 canbe interrupted, e.g., by providing holes with which the metal mesh caninteract, e.g., by at least a partially interlocking interaction. Insome variations, the mesh is self-expanding. In these variations,expandable member 901 may be omitted. A sleeve (not shown) may beinstalled around self-expanding mesh to constrain the outer diameter ofthe mesh. When the sleeve is removed, e.g., by retraction, the mesh isable to expand outwardly to lock tether 534 between the mesh and tube900. Self-expanding mesh may be made of materials such as shape-memorymetals or superelastic metals.

A hollow locking element having features that protrude towards itsinterior can be used to fix tether 534 during termination. An example ofsuch a locking element 930 is provided in FIG. 24A. Tether 534 isthreaded through hollow locking element 930. Features 931, such asbarbs, flaps, or prongs, protrude inwardly. An inner cross-sectionaldimension of element 930 is small enough such that at least some offeatures 931 contact tether 534 as it is threaded through element 930.Features 931 are angled in a proximal direction, such that lockingelement 930 can be slid in a distal direction until it reaches or isclose to most proximal anchor 526. Because features 931 are angled in aproximal direction, and at least some of features 931 contact tether534, motion in the opposite direction (i.e., sliding element 930 in aproximal direction) will be opposed by features 931 exerting forceagainst tether 534. In some cases, features 931 may be flexible to easethe pulling of tether 534 through element 930 in a distal directionduring the cinching of tether 534. In some variations, features 931 canbe sharp enough or small enough in dimension so as to become interlockedwith inter-thread spaces in tether 534. Locking element 930 can beprepared by any suitable method. For example, as illustrated in FIG. 25,V-shaped grooves 932 can be cut into a metal tube (e.g., by using alaser). The resulting V-shaped metal pieces can be bent inward, forminga cross-section of element 930 similar to that illustrated in FIG. 24A.A plug that fits into a collar can be used to lock the tether duringtermination.

Collars comprising deformable materials can also be used to lock thetether during termination. Examples of these variations are illustratedin FIGS. 26A-B and FIG. 27. As shown in FIG. 26A, tether 534 can bethreaded through a cylindrical collar 1020 and deformable ring 1024positioned in the interior of collar 1020 and seated on a base 1022 ofcollar 1020. Ring 1024 can be any suitable deformable ring, such as anO-ring. Before locking the tether during termination, tether 534 canslide freely through cylindrical collar 1020. When fixing the tetherinto place, pushing element 1026 is pushed into the interior of collar1020 such that ring 1024 is compressed, thus reducing its inner diameter(FIG. 26B). Ring 1024 is chosen such that its inner diameter whencompressed is small enough to restrict movement of tether 534.Alternatively, 1024 could be a shape other than a ring, such as two ormore portions which are compressed so that they grip tether 534 betweenthem. Pushing element 1026 can be pushed into collar 1020 by anysuitable technique. For example, the interior of collar 1020 and element1026 can be threaded, such that element 1026 can be screwed down tocompress ring 1024. Alternatively, pushing element 1026 can have afriction fit with collar 1020 to compress ring 1024. In othervariations, the pushing element is spring loaded such that it fits intocollar 1020 and can compress ring 1024. In still other variations, anadditional cap or spring (not shown) can be applied to push element 1026down to compress ring 1024. As illustrated in FIG. 27, the interior ofcollar 1030 and the exterior of pushing element 1032 can be configuredsuch that element 1032 is ratcheted along the interior of collar 1030when force is applied, thus compressing ring 1034 and constrictingtether 534 such that it cannot slide. For the embodiments shown in FIGS.26A-B and FIG. 27, rings 1024, 1034 can have any suitablecross-sectional shape and be made of any suitable material. For example,in some cases, it may be desired that rings 1024, 1034 have round orpolyhedral, e.g., octahedral, cross-sectional shapes. Material for rings1024, 1034 can be chosen for any desired property, such asdeformability, biocompatibility, or coefficient of friction with thematerial used for tether 534. In other variations, the tether can beclamped by altering a path of the tether through a locking feature toincrease the frictional forces on the tether. For example, the tethercan be threaded through a network of rollers or pins to lock the tetherin place during termination.

As shown in FIGS. 28A-B, clamps containing actuated clamping elementscan be used to lock the tether in place during termination. For example,clamp 1060 containing clamping elements 1064 and 1066 can be used. Clamp1060 has first side wall 1062 with a profiled inner surface 1072 andopposite side wall 1068. Actuator channel 1074 is provided between sidewall 1068 and elements 1064 and 1066. Elements 1064 are arrangedgenerally collinearly with and alternated with elements 1066 along alength of clamp 1060, such that elements 1064 protrude further intoactuator channel 1074. Tether 534 is threaded through channel 1076between elements 1064, 1066 and profiled inner surface 1072 of firstside wall 1062. As actuator 1070 is forced into actuator channel 1074,actuating elements 1064 are preferentially pushed into channel 1076,creating a tortuous path for tether 534 that is threaded through channel1076 (FIG. 28B). In some cases, actuating elements 1064 have roundededges where actuator 1070 will slide against them to force them intochannel 1076. Profiled inner surface 1072 can have any suitable profileto lock tether 534 during termination. In some variations, a lockingdevice made from a single piece can be used to accomplish the samelocking principle as exemplified in FIGS. 28A-B. For example, as shownin FIG. 28C, locking device 1080 can be used. Locking device 1080comprises a first side wall 1082 having first profiled inner surface1092. Middle wall 1084 having second profiled inner surface 1090 isprovided opposite first inner surface 1092. Second side wall 1086 isprovided, separated from middle wall 1084 by actuator channel 1087.Tether 534 is threaded through channel 1084 between surfaces 1090 and1092. Before locking device 1080, tether 534 can move freely throughchannel 1084. When it is desired to lock tether 534 using device 1080,an actuator 1091 can be inserted into actuator channel 1087, forcingprofiled surfaces 1090 and 1092 together, thus creating a tortuous pathfor tether 534, and preventing it from slipping through device 1080.

Adhesive may be used to facilitate the locking of the tether. Forexample, drops of adhesive material may be applied, e.g., released froman applicator, to bond the tether to any locking mechanism. For example,adhesive may be applied to knots (see FIGS. 16A-E, for example),clamping devices (see FIGS. 19-23, for example), or to protrusions onthe tether (see FIGS. 17 and 18A, for example). Pressure activated orpressure sensitive adhesives may be used. For example, with reference toFIG. 23A-C, the exterior of mesh 902 and or the interior of tube 900 canbe at least partially lined with a pressure activated or pressuresensitive adhesive.

After the tether is locked to prevent it from slipping through the mostproximal anchor, the excess tether must be cut so it can be removedduring termination. Generally, the tether is cut proximal the lockingmechanism. In many cases, it is desired to cut the tether as closely aspossible to the locking mechanism, while leaving enough excess length toallow for any slippage that may occur. The following examples providevarious methods and devices for cutting the excess tether.

In some variations, concentric tubes can be used to cut excess tether.One concentric tube can be advanced relative to another concentric tubeto shear off excess tether at a desired position. Alternatively, oneconcentric tube can be rotated with respect to another concentric tubeto cut the tether. For example, as shown in FIG. 29A, in someembodiments, tether 534 has been cinched and is fixed relative to mostproximal anchor by locking feature 744. Although locking feature 744 isshown herein as separate from the most proximal anchor for illustrativepurposes, locking feature 744 can also be part of, or integral with, themost proximal anchor. In addition, locking feature 744 can be locatedexternal or internal to a catheter or other intravascular device. Tether534 enters a catheter 745 and exits through a side opening 746. Tether534 can be loaded into catheter 745 by any suitable method, for examplethose described herein in FIGS. 14-15. A cutting tube 747 having an edge748 sharp enough to cut tether 734, e.g., a metal tube having asharpened edge, is attached to a flexible tube or to a rod and isadvanced inside the catheter over side opening 746 from which tether 534extends. As it is advanced over tether 534, cutting tube 747 can shearoff the excess portion of the tether. In some variations, as shown inFIG. 29B, cutting tube 747 is advanced against a base 749 that canassist tube 747 in cutting through tether 534. Base 749 can for examplebe a block positioned on the interior of catheter 745. Alternatively,base 749 can be part of catheter 745 or be formed integrally withcatheter 745. Base 749 can be formed of any suitable material, e.g., anyelastomeric or rigid material. In some variations, cutting tube 747 canbe spun or rotated to improve cutting. The profile of cutting tube 747can be any suitable shape, for example V-shaped or triangular, as shownin FIGS. 29C-E. In addition, cutting tube 747 may have a serrated orsaw-tooth pattern of sharp protrusions around its perimeter to aid incutting. Such variations may be used for example when tube 747 is spunor rotated during the cutting process. In some variations, as shown inFIG. 29F, cutting tube 747 can be positioned in front of hole 746 suchthat cutting tube 747 can be pulled in a proximal direction toward hole746 to cut tether 534 (indicated by solid arrow).

Alternatively, a cutting tube can be provided that is external to acatheter housing tether 534. For example, as shown in FIG. 30A, tether534 extends through catheter 745 and exits through hole 746. Again,tether 534 can be loaded into catheter 745 by any suitable method,including methods described herein. Cutting tube 750, which can be asharpened metal tube, can slide along the exterior of catheter 745. Insome variations, cutting tube 750 is attached to a second tube 751 whichslides along the exterior of catheter 745. Second tube 751 can beflexible. As cutting tube 750 is advanced in a distal direction towardhole 746 (indicated by solid arrow), end 753 of tube 750 can severtether 534. As shown in FIG. 30B, a base 754 can be positioned alongcatheter 745 such that tether 534 is pushed against base 752 as cuttingtube 750 is advanced toward hole 746, thereby improving the cuttingprocess. As also shown in FIG. 30B, a cover or shroud 754 can beprovided around cutting tube 750 in some variations to prevent sharpenedend 753 from catching on tissue or the like. In some variations, cover754 is attached to second tube 751.

Cutting tubes can have any suitable shape. For example, as shown in FIG.31A, cutting tube 760 can have a V-shape along its perimeter or othernotched feature designed to channel tether 534. Alternatively, cuttingtube 760 can have a curved profile (FIG. 31B), an angled profile (FIG.31C), a serrated profile (FIG. 31D), or a saw tooth profile (not shown).The latter two variations may be useful when cutting tube 760 is rotatedor spun during the cutting process. In some variations, the perimeter ofhole 746 is sharpened to cut tether 734. The cutting tubes can beconfigured such that they operate either externally or internally tocatheter 745.

In some variations, cutting tubes can sever the tether by cutting in adirection roughly perpendicular to the long axis of the catheter, e.g.,by rotating one concentric tube relative to a second concentric tube. Asillustrated in FIG. 32A, tether 534 enters catheter 745 and exitsthrough hole 746. Cutting tube 770 can be configured such that when itis rotated about the long axis A-A′ of catheter 745, it can slice tether534. For example, cutting tube 770 can have an angled shape such thatwhen it rotates about axis A-A′ it cuts tether 534. In some variations,cutting tube 770 is attached to a flexible tube 771. In othervariations, a blocking structure 773 is disposed on catheter 745.Blocking structure 773 can have any suitable shape, and can serve as abase against which tether 534 can be pushed during the cutting process.Block 773 can be attached to, part of, or integral with catheter 745.Alternatively, as shown in FIG. 32B, the cutting tube 772 can have aprofiled shape to enable it to cut tether 534 in a direction generallyorthogonal to long axis A-A′ of catheter 745 as it is rotated aroundaxis A-A′. Optionally a blocking structure 774 can be provided oncatheter 745 such that tether 534 is pushed against block 774 during thecutting process. Block 774 can be any suitable shape or have andsuitable configuration and can be attached to, part of, or integral withcatheter 745. Cutting tubes such as those illustrated in FIGS. 32A-B canbe configured such that they are internal to the catheter.

In some variations, a pair of concentric cutting tubes can be used tocut the tether. The concentric tubes can be either internal or externalto the catheter. As illustrated in FIG. 33, the two concentric cuttingtubes 780 and 781 can be rotated about the long axis A-A′ of catheter745 in opposite directions (indicated by solid arrows). Thus, thecutting edges 782 and 783 can cut tether 534 in a scissor-like fashion.Cutting edges 782 and 783 can be sharpened in such a way to enable edges782 and 783 to pass each other as closely as possible.

In some variations, the tether does not exit the catheter through a sidehole. In these variations, a cutter can be mounted on a tube concentricto the catheter, either externally or internally, and rotated to cut thecable. For example, as shown in FIG. 34A, excess tether 534 proximallocking feature 744 enters catheter 792 through its end opening 794.Optionally catheter 792 can have lips 793 that restrict the diameter ofthe end opening 794. A concentric tube 791 has attached thereto a blade790, which can be rotated to sever excess tether 534. FIG. 34Billustrates the operation of blade 790 on tether 534 as it is rotated.

Alternatively, as shown in FIG. 34C, two concentric tubes 795 and 798can be provided. Tube 795 has blade 796 attached to its end; tube 798has blade 797 attached to its end. Blades 796 and 797 are orientedgenerally perpendicular to the long axes of tubes 795 and 798. The tubes795 and 798 are rotated in opposite directions about their respectivelong axes to cut tether 534. FIG. 34D illustrates the operations ofblades 796 and 797 on tether 534 as they are rotated. Blades 796, 797can be configured such that sharpened edges pass each other closelyenough and at such angles to facilitate cutting. The cutting blades 790,796, and 797 can have any suitable shape, e.g., angled, V-shaped, orcurved. The concentric tubes 795, 798 can be mounted either external orinternal to catheter 792. For example, one tube can be external whilethe other is internal.

In some variations, as illustrated in FIG. 35A, a hook, loop or the likecan be used to engage the tether between the most proximal anchor andthe distal end of the catheter. Tether 534 is cinched, locked into placeby locking feature 744, and threaded lengthwise through catheter 801 inchannel 807 between an inner wall of catheter 801 and cutting tube 802.Cutting tube 802 has a sharpened edge 803 on its distal end. Assembly804 having hook 805 on its distal end is configured such that it extendsthrough cutting tube 802. Hook 805 engages a portion 806 of the excesstether that extends proximally from locking feature 744. The length oftether 534 threaded through channel 807 is pulled in a proximaldirection. Hook 805 can pull portion 806 of tether 534 in a proximaldirection (indicated by solid arrow), forcing the tether againstsharpened edge 803, which severs the excess tether. Alternatively, hook805 can include a sharpened edge or blade such that it can cut tether534.

As described above, the tether cutter may comprise any appropriatestructure or material. For example, in addition to the cutting tubesdescribed above, the tether cutter may cut by heat, electricity,chemical reaction, or the like. For example, the tether cutter maycomprise an electrode or filament through which electrical energy may beapplied to cut the tether.

In other variations, as illustrated in FIG. 35B, tether 534 can bethreaded through a collet 810 comprising a housing 811. Housing 811 canbe coupled to catheter 817. Tether 534 is threaded through collet 810such that a loop 812 of tether 534 extends in a proximal direction fromcollet 810. Collet 810 can have any suitable shape, e.g., U-shaped orC-shaped. A hook or loop 813 coupled to apparatus 815 can be used toengage loop 812. A pusher 814 can be used to apply force in a distaldirection to collet 810 while hook 813 is pulled in a proximal directionby apparatus 815. As hook 813 is pulled in a proximal direction, tether534 is forced against cutting blade 818. Cutting blade 818 can have anysuitable orientation or configuration such that tether 534 can be forcedagainst a cutting surface of cutting blade 818. Cutting blade 818 can beattached to, part of, or integral with housing 811. Optionally, a collar816 can be placed between collet 810 and pusher 814 to aid in applyingforce to collet 810. In some variations, collet 810 can be placedinternal to catheter 817, and housing 811 can be omitted. In thosevariations, catheter 817 can comprise a cutting blade (not shown)attached to, part of, or integral with the catheter and configured suchthat as loop 812 of tether 534 is pulled in a proximal direction, tether534 is forced against the cutting blade. In some variations, hook 813can be capable of cutting tether 534 as tension is applied. In thosevariations, cutting blade 818 may be omitted. In FIG. 35B is that hookor loop 813 draws the end of the tether is drawn into collet 810. Then,tube 814 pushes down 816 around 810 to lock in the tether 534. Theassembly of tether, collet and collar 534, 810, 816 is released alltogether, becoming an element which locks the tether and preventsslipping through the most proximal eyelet.

In other variations as shown in FIG. 35C, tether 534 can be threadedthrough a one-way locking mechanism 820 provided internal to catheter821. Locking mechanism 820 can be separate from, e.g., part of aseparate tube, or attached to catheter 821. Locking mechanism 820comprises opposing angled flaps 824. The flaps are angled in a proximaldirection and closely spaced such that the tether can be pulled throughmechanism 820 in a proximal direction forming a loop 822 extending in aproximal direction from mechanism 820. A hook 823 coupled to apparatus824 engages tether loop 822. Once the tether is cinched to the desiredtension by pulling loop 822 proximally and locked into place by lockingdevice 744, tether 534 can be pulled in a distal direction and cut bycutting edges 825 provided as part of flaps 824. Optionally, cuttingedges 825 can be serrated or comprise teeth to aid in cutting. FIG. 35Cillustrates a locking device that is an alternative to the device shownin FIG. 35B. Here, instead, the loop 822 is pulled through and locked.Then, the whole thing (locking flaps and loop) is released to be the“lock” that prevents slipping the tether from slipping through theeyelet.

As shown in FIG. 36A, cutting apparatus 834 comprising single angledflap 826 can be used to cut excess tether. Cutting apparatus 834 can beinternal to a catheter (not shown) or part of a catheter. Cuttingapparatus 834 comprises wall 828, opposite flap 826. In some variations,wall 828 is a wall of a tube. In other variations, both surface 828 andflap 826 are formed from the same tube. Flap 826 is angled in a proximaldirection and abuts or is in close proximity to wall 828. Tether 534 canbe threaded between flap 826 and wall 828 by pulling in a proximaldirection. However, when force is applied to pull tether 534 in a distaldirection, cutting edge 829 of flap 826 digs into and severs tether 534.

As shown in FIG. 36B, in some variations a cutting apparatus 835comprising multiple angled flaps can be provided. Several spaced apartor staggered flaps 830 having cutting edges 833 are provided oppositewalls 836. Flaps 830 are angled in a proximal direction and abut or arein close proximity to opposing walls 836. Tether 534 can be threaded ina proximal direction between walls 836 and flaps 830. When tether 534 ispulled in a distal direction, cutting edges 833 dig in and operate tosever tether 534. For the variations shown in FIGS. 35D-E, cutting edges829, 833 can be configured in any suitable manner, e.g., they may besharpened blades, comprise a serrated cutting edge, or comprise teeth.

As shown in FIG. 37, a cutter can be mounted on a balloon within acatheter. An excess portion of tether 534 proximal to locking device 755enters catheter 837 at its distal end and exits through side hole 831.Expandable member 832 is provided within catheter 837 and is adjacent tothe section of tether 534 within catheter 837. Expandable member 832 canbe, for example, a balloon, or more than one balloon. Attached to theperimeter of the expandable member are cutters (e.g., blades) 838capable of cutting tether 534. Expandable member 832 can be expandedsuch that tether 534 is pressed between an interior wall of catheter 837and cutter 838. When in its expanded state, expandable member 832 can berotated along an axis generally parallel to the long axis of catheter837 to cut tether 534. For example, if expandable member 832 comprises aballoon, the balloon can be inflated to an amount such that cutter 838is pressed against tether 534 but the balloon can still be rotatedwithin catheter 837. Cutter 838 can have any suitable shape orconfiguration. In some variations, a single blade 838 can be attached toexpandable member 832 that is capable of cutting tether 534. In othervariations, cutter 838 can sever tether 534 by virtue of the blade beingpressed into the tether by the expandable member, and thus need not berotated to a substantial degree to sever tether 534. In some variations,a deformable mesh tube (not shown) can be provided to at least partiallyencase expandable member 832. Thus, as expandable member 832 isexpanded, it can cause the mesh tube to expand against tether 534,sandwiching it between the mesh and tube 837 to hold tether 534 inplace.

As shown in FIGS. 38A-D, tether 534 can be threaded through cuttingapparatus 839 comprising a guillotine-like blade and an opposing cuttingblock. The excess portion of tether 534 proximal locking device ormechanism 744 is threaded into catheter 840 between side wall 841 andpin 842. Tether 534 then traverses part of the inner diameter ofcatheter 840 and is threaded between opposite side wall 843 and pin 844.Blade 845 is provided on one side of portion 847 of tether 534 extendedbetween pins 842 and 844. Blade 845 is mounted in any suitable manner,e.g., on a bridge 848 at least partially within catheter 840.Optionally, a cutting block 846 is provided across tether portion 847and opposite blade 845. As tension is applied to tether 534 in aproximal direction (indicated by solid arrow), blade 845 can be forcedagainst tether portion 847, thus severing the tether. Blade 845 can cutagainst cutting block 846, when present. As shown in FIG. 38C, a toolcomprising a pair of blades connected with a pivot (e.g., a scissor-liketool) 850 can be provided to cut the tether. Tool 850 can operate withinor external to catheter 840. Rods 851 connected to opposing blades 852of tool 850 can be pulled or pushed to sever tether 534. As shown inFIG. 38D, tether 534 can be threaded between catheter side wall 841 andpin 842, between pin 842 and pin 860, and between pin 844 and oppositeside wall 843. A sharpened blade or hook 861 can be pulled across tetherportion 847 which extends between pins 842 and 844 to cut tether 534.

In some embodiments, cinching tether 534, fixedly coupling tether 534 tomost-proximal anchor 526, and cutting excess tether 534 are achievedusing a single or integrated termination device (not shown). Thetermination device may comprise, for example, a catheter that can beadvanced over tether 534 that includes a cutting member and a knot,other attachment member, or a locking device for attaching or fixedlycoupling tether 534 to most-proximal anchor 526. The terminationcatheter may be a steerable catheter. The termination catheter may beadvanced over tether 534 to a location at or near the proximal end ofthe tethered anchors 526. The catheter may then be used to applyopposing force to the most-proximal anchor 526 while tether 534 iscinched. The attachment member may be used to attach tether 534 tomost-proximal anchor 526 and the cutting member may be used to cuttether 534 just proximal to most-proximal anchor 526. Such a terminationdevice is only one possible way of accomplishing the cinching,attachment and cutting steps, and any other suitable device(s) ortechnique(s) may be used.

A termination device can incorporate the termination functions ofcinching the anchors with a tether, locking the cinching tether, andcutting away the excess length of the cinching tether in many ways. Insome embodiments, a deployment device can deploy the anchors into thetissue to be tightened, and also cinch and lock the tether. A separatedevice can them be employed to cut the tether. Alternatively, the anchordeployment device can deploy the anchors into the tissue, cinch, lockand cut the tether. In other variations, three separate devices can beused in termination: an anchor deployment device; a second device tocinch the tether and lock the tether; and a third device to cut thetether. Termination functionalities can be integrated in any suitablemanner in one or more termination devices. In addition, any number orcombination of devices can be used in the termination procedure.Provided below are several possible architectures for terminationdevices that combine or integrate termination functions. These devicesare only exemplary devices.

For example, with reference to FIGS. 23A-C, a balloon or otherexpandable member 901 can be inflated to expand a metal mesh 902 toclamp tether 534 between mesh 902 and an outer tube 900. Subsequently, asharpened tube can be advanced to cut the tether. For example, if thetether is threaded through a side hole, the sharpened tubes that areprovided in FIGS. 30A-B, 31A-D, and 32A-B can be used to cut the tetheras indicated in the figures. If the tether is not threaded through aside hole, cutters such as are illustrated in FIGS. 34A-D can be used.Any suitable cutting technique can be also be used to sever the excesstether.

In another example, with reference to FIG. 37 and FIGS. 23A-C, theexpandable member or balloon 832 of FIG. 37 can be inflated to expand ametal mesh (not shown in FIG. 37 but similar to mesh 902 as illustratedin FIGS. 23A-C) to compress the tether 534 between the mesh and outertube 837. Cutting mechanism 838 is mounted to expandable member 832.Expandable member 832 can be configured such that the portion of theexpandable member to which cutter 838 is mounted inflates after themetal mesh is expanded. For example, expandable member 838 can comprisetwo separate balloons, one of which has cutting mechanism 838 attachedthereto. When the portion of member 832 comprising cutter 838 isexpanded, cutter 838 cuts tether 534. Alternatively, a cutter or cutters838 can be rotated to sever tether 534. Once the tether has been cut,the mesh locking mechanism applied to the tether can be released, e.g.,by advancing a pusher (not shown).

In another example of an architecture of a termination device, withreference to FIG. 37 and FIGS. 16A-E, a multi-stranded half-knot intether 534 can be pushed down to lock tether 534 in place. Thenexpandable member can be inflated and rotated at least partially withincatheter 837 such that cutters (e.g., blades) 838 cut tether 534.Alternatively, with reference to FIGS. 30A-B, 31A-D, 32A-B, 33, and34A-D as examples, any type of tube-mounted cutter can be used to severtether 534. For cutting devices such as those illustrated in FIGS.30A-B, 31A-D, 32A-B, and 33, in which tether 534 is threaded through aside hole (e.g., side hole 746 in FIGS. 30A-B) to enable cutting,additional tethers or cables used to form multi-stranded knot 721 canalso be threaded through the side hole and cut. Any other type ofcutting mechanism described herein can be used in combination with atether locking mechanism employing a multi-stranded half-knot to fixtether 534.

With reference now to FIGS. 13A and 13B, one embodiment of a steerablecatheter device 560 is shown. Steerable catheter device 560 may be usedin a method such as that just described in reference to FIGS. 12A-12F,for example in performing a function similar to that performed by secondguide catheter 554. In other embodiments, catheter device 560 mayperform any other suitable function, e.g., any of the terminationfunctions described herein. As shown, catheter device 560 suitablyincludes an elongate catheter body having a proximal portion 562 and adistal portion 564. At least one tensioning member 568, such as but notlimited to a tensioning cord, extends from proximal portion 562 todistal portion 564 and is coupled with the distal portion 564 and atleast one tensioning actuator 570/572 on the proximal portion.Tensioning actuator 570/572 may include, for example, a knob 570 and abarrel 572 for wrapping and unwrapping tensioning member 568 to applyand remove tension. Tensioning member 568 is coupled with distal portion564 at one or more connection points 580. In some embodiments, catheterdevice 560 includes a proximal housing 571, handle or the like, coupledto the proximal end of proximal portion 562 via a hub 576 or othermechanism. Housing 571 may be coupled with tensioning actuator 570/572and may include one or more arms 574 for infusing fluid or for otherfunctions. In the embodiment shown, arm 574 and housing 571 include alumen 567 that is in fluid communication with a fluid lumen 566 of thecatheter body. Fluid may be introduced through arm 574 to pass throughfluid lumen 566 to provide, for example, for contrast material at thedistal tip of catheter device 560 to enhance visualization of device 560during a procedure. Any other suitable fluid(s) may be passed throughlumens 567/566 for any other purpose. Another lumen 578 may be includedin distal portion 564, through which tensioning member 568 passes beforeattaching at a distal location along distal portion 564.

FIG. 13B shows catheter device 560 in a deformed/bent configuration,after tension has been applied to distal portion 564 by applying tensionto tensioning member 568, via knob 570 and barrel 572. The bend indistal portion 564 will allow it to conform more readily to a valveannulus, while catheter device 560 in its straight configuration will bemore amenable to passage through vasculature of the patient. Tensioningmember 568 may be manufactured from any suitable material or combinationof materials, such as but not limited to nickel titanium alloys,polyester, nylon, polypropylene and/or other polymers. Some embodimentsmay include two or more tensioning members 568 and/or two or moretensioning actuators 570/572 to provide for changes in shape of distalportion 564 in multiple directions. In alternative embodiments, knob 570and barrel 572 may be substituted with any suitable devices, such as apull cord, button, lever or other actuator. Various alternatives mayalso be substituted for tensioning member 568 in various embodiments.For example, shaped expandable members, shape memory members and/or thelike may be used to change the shape of distal portion 564.

Generally, proximal portion 562 of the catheter body is less flexiblethan distal portion 564. Proximal portion 562 may be made of anysuitable material, such as PEBAX® elastomers, fluoroethylene propylene,nylon, polyethylene and/or the like, and may include a braided material,such as stainless steel, to provide stiffness and strength. Distalportion 564 may be made of similar or other materials, but the braidedmaterial is typically not included, to provide for greater flexibility.Both proximal and distal portions 562/564 may have any suitable lengths,diameters, overall configurations and the like. In one embodiment thecatheter body is approximately 140 cm in length and 6 French indiameter, but any other suitable sizes may be used in other embodiments.Proximal portion 562, distal portion 564 or preferably both, may be madefrom or coated with one or more friction resistant or lubricatingmaterial to enhance passage of device 560 through an introducer catheterand/or to enhance passage of a sheath or other device over catheterdevice 560.

As described above, the termination devices described herein may beintegrated termination devices, including tether cutters, lockingfeatures, tensioning devices, positioning devices, and the like.Provided below are exemplary termination devices including many of thesefeatures.

EXAMPLES

In general, termination devices are designed to cinch, lock, and/or cuta tether (e.g., a suture or cable) as described herein. These devicescan be used for any surgery where these functions (or combinations ofthem) are desired. FIG. 39 shows a termination device 3901 having adetachable locking feature 3905 that is releasably attached at thedistal end of the termination device. This variation of a terminationdevice has an elongated tubular body 3903 which may be flexible over all(or a portion) of its length. Thus, the termination device may be usedin non-invasive procedures (e.g., percutaneously) or in invasive (e.g.,open-heart) surgeries. The termination device shown in FIG. 39 isconfigured as a termination device catheter.

The termination device 3901 shown in cross-section in FIG. 39 is coupledto a tether 3910. The tether is threaded through the distal region ofthe termination device, particularly through the locking feature 3905region at the distal end of the termination device. Although any lockingfeature may be included as part of the termination device, as describedabove, the locking feature shown in FIG. 39 is a clamping type lockingfeature in which a plug 3913 fits into a hollow region of the lockingfeature and secures the tether between the plug and a wall of thelocking feature. The tether passes through one or more openings (e.g.passages or holes) on the side of the device. Until the locking featureis secured, the termination device may be moved along the tether (e.g.,by sliding), or the tether may be pulled through the termination device.Thus, the tether may be cinched by sliding the termination device down(distally) the tether.

The openings through the termination device may be positioned such thatthe device can still easily slide along the tether (cinching cable). Thetether may be threaded into the locking feature in such a way that itwinds in and out of the tube, as suggested by the drawings. This mayhelp the cable slide more easily, because under tension, the cable isfree to wind less tightly around the features on the tube (e.g. closerto straight path). The cable may be threaded or coupled to thetermination device during manufacturing or by the user. As shown inFIGS. 14A and 14B, a wire loop (or lasso) may be threaded through theopenings. Then, after inserting the tether through the loop, theopposite end of the loop can be pulled to thread the tether through theopenings. In some variations, the termination device may be slid alongthe tether until the tether is cinched to the desired size through theanchors, and then secured into position using the locking feature. Forexample, in FIG. 39, the locking feature is secured by moving the plug3913 into position within the hollow portion of the locking feature3905, where it secures (holds) at least a portion of the tether 3910. Inthe variation shown in FIG. 39, the plug 3913 secures the tether 3910 bycompressing at least a portion of the tether between the plug and theinner walls of the locking feature and forcing the tether to windthrough the tube through sharp turns. The locking feature (including theplug) may comprise features that prevent the release of the plug fromthe locking feature. For example, the locking feature may includeadhesive or cement, or it may be at least partly deformable so that oncethe plug is inserted into the distal tip (e.g., locking feature) regionof the termination device, it is retained at the distal tip.

The termination device shown in FIG. 39 also includes a plunger or pushrod 3915 for pushing the plug 3913 into position to secure the tetherwithin the locking feature of the termination device. The plunger shownmay be slidable within the lumen of the termination device. In somevariations, the rod may include guides (e.g., guiding the direction) orstops (e.g., limiting the distance that the rod may travel, or the forcethat may be applied by the rod). Thus, there may be motion-limitingfeatures on the termination device and/or rod to prevent the rod frombeing pushed too far forward, or applying too much force, which coulddisturb either the locking mechanism or the tissue (e.g., afterseparation of the locking mechanism from the rest of the terminationdevice).

The locking feature may be detachably connected to the rest of thetermination device. For example, the locking feature may be frangibleconnected to the termination device, so that it can be detached from thetermination device by breaking the connection between the lockingfeature and more proximal portion of the body of the termination device.Thus, the locking feature e.g., tube, clamp, knot, etc.) can be attachedto the rest of the termination device so that it can be separated. Thelocking feature may be detachably connected to the rest of thetermination device by any appropriate method. Thus, the locking feature(or a portion of the locking feature) may include a releasablyattachment region. The releasable attachment region may include anyregion that can be separated or broken to release the locking featurefrom the elongate body of the termination device. For example, thereleasable attachment region may comprise a region where the lockingfeature is fused to another region of the termination device (e.g., thedistal region of the elongate body).

In some variations the locking feature is fused by melting the materialscomprising at least a portion of the locking feature and a portion ofthe rest of the termination device. The two materials may be fusedtogether to different degrees (e.g., by varying the number of fuse spotsor area of fusing) to adjust the force necessary to separate the tworegions of the termination device. The different regions of thetermination device may comprise different materials, or may comprise thesame material. In some variations, the fused region comprises a thirdmaterial used to secure the two regions together until they areseparated. Being able to use different materials for different regionsof the termination device may be advantageous if there are differentmaterial requirements for the different regions of the terminationdevice, for example if the more distal portion of the termination deviceneeds to be more flexible, and the more proximal region needs to bestiffer, or vice-versa.

In some variations, the detachable locking feature of the terminationdevice is attached to the rest of the termination device by a releasableattachment region that has been structurally weakened between thelocking feature and the rest of the termination device. For example, thetermination device may comprise a scored, etched, perforated, fractured,creased, slotted or dimpled region between the locking feature and therest of the termination device. An example of a perforated region 3120is shown in FIG. 39. Thus, the locking feature may be composed of thesame material as the rest of the termination device (or it may be madeof different materials that have been fused together). Scoring,perforating or other wise weakening the region between the lockingfeature and the more proximal portion of the termination device mayallow the locking feature to be separated from the rest of thetermination device when enough force is applied (e.g., to thetermination feature by the push rod, as described above). The detachablelocking feature could also be attached via an adhesive or a friction fitso that applying a certain amount of force causes the two regions of thetermination device to separate, releasing the detachable lockingfeature. The two materials can also be welded, brazed, soldered, orsnap-locked.

As described above, the locking feature can be controllably releasedfrom the rest of the termination device by applying force. Force may beapplied in any appropriate manner (e.g., pushing on a push rod,hydraulic force (e.g., saline etc.), magnetic force, pressure, etc.).For example, the same push rod 3915 used to push the plug 3913 andsecure the locking feature may be used to separate the locking featurefrom the rest of the termination device by simply pushing withadditional force. In some variations, a separate force applicator may beused to secure the locking feature (e.g., a push rod) and to separatethe locking feature from the rest of the termination device (e.g., asecond push rod). Furthermore, the amount of force required to releasethe detachable locking feature may be predetermined. In variations wherethe locking feature is locked or triggered by the same force applicator(e.g., push rod), the force required to detach the locking feature maybe greater than the force required to secure the locking feature(locking the tether). For example, the termination device may beconfigured to release the detachable locking feature after theapplication of greater than about 2 lbs of force, greater than about 3lbs of force, greater than about 4 lbs of force, greater than about 5lbs of force, greater than about 10 lbs of force, greater than about 20lbs of force, or between about 2 lbs and about 5 lbs of force. Thetermination device may be configured to detach the locking feature byselecting an appropriate junction between the locking feature and therest of the termination device (e.g., the thickness, material(s),scoring/perforations, etc.). In some variations, the force applicatorused to release the locking feature (e.g., the push rod, fluid line,magnet, etc.) may be configured to apply a controllable force necessaryto detach the locking feature. Thus, the force required to separate thelocking feature from the rest of the termination device can be adjustedby fusing the materials of the locking feature and the body of thetermination device together more or less, by adjusting the amount ofperforation, or by changing the adhesive application or friction fit.Further, the amount of force and the way that force is applied to detachthe locking feature may be controlled to prevent damage to the lockingfeature, the tether, the anchors, and/or the surrounding tissue. Thelocking feature may also be released by cutting the joint between it andthe rest of the termination catheter (e.g., by a shearing blade thatslides to shear the fuse joint). A cutter may also cut the cable and thejoint in a combined manner, thus completely releasing the lockingmechanism with the cable severed.

Although we have described only a few of the ways that a locking featuremay be detachably connected to a termination device, it should beunderstood that any appropriate attachment may be used, including snapfits and attachment mechanisms (e.g., threads, etc.). The attachmentsdescribed herein may be readily scaled in size for use with evenapplications requiring very small locking features (e.g., duringpercutaneous applications).

In operation (e.g., during an annuloplasty procedure), a locking featureis typically secured to the tether to fix its length (in some casescinching the tether), such that the end of the tether does not slidethrough the eye of the most proximal anchor, as described above. Afterthe tether is locked, the excess length of tether may be cut andremoved.

Typically, cinching occurs by applying tension to the tether whilebracing the termination device (e.g., including a locking feature)against the most proximal anchor. The tether may slide through thetermination device when the locking feature is not in a secured state.After the desired amount of cinching is achieved, the locking feature isengaged, locking the suture in place. For example, the terminationdevice shown in FIG. 39 can be used to secure a tether (e.g., cinchingan annulus) by applying force from a push rod to push the plug 3913 intothe locking feature and secure the tether. The end of the lockingfeature shown in FIG. 39 comprises an outer tube that is partially orcompletely closed (narrowed) so as the plug is pushed in, it is heldsecurely against the tether. As described above, the plug may comprise amaterial which is compressible or elastic to aid in locking the pluginto the end of the locking: feature. In some variations, a portion ofthe locking feature may be configured to secure the locking feature inthe locked position, and/or to secure the tether. For example, the plug3913 shown as part of the locking feature in FIGS. 39 and 40 may havepolygonal (e.g., hexagonal) sides that interact with the inner surfaceof the locking mechanism. The plug maybe solid or hollow. The plug mayhave bumps, dimples, ribs, grooves or holes on the surface to increasetraction on the cable. The locking feature may also include structures(e.g., rims, brackets, etc.) to help hold the plug in the lockedconfiguration. Thus, this locking feature (like most of the lockingfeatures described above) has an unsecured state, in which the tethermay move with respect to the locking feature, and a secured state, inwhich the tether is secured or held by the locking feature. Once thetether is locked into position, the push-rod can be further advanced toseparate the locking feature from the rest of the termination device.The outer tube may also be polygonal in cross-section.

As described above, any appropriate locking feature may be used. Forexample, the locking feature may comprise a kinking tube that is kinkedto secure a tether by a plug. In one variation, the tether passes insideof an outer tube of the locking feature through a pre-kinked smallertube. When passing and cinching the tether, the tether is tensioned,causing the pre-kinked inner tube to straighten and thus lower thesliding force required to move the tether in the termination device.When it is desired to secure the locking feature, a plug can be pushedinto the outer tube to buckle and kink the pre-kinked inner tube tosecure the tether in very tight windings, locking the tether inposition. FIGS. 42A and 42B show one variation of a termination devicehaving a locking feature that fixes a tether in a tight winding pathwithin the locking feature to secure the tether. In FIG. 42A, thelocking feature is shown in the unlocked state, when the inner tube 4207is un-kinked, allowing the tether 3910 to pass freely though the lockingfeature (e.g., the outer tube 4210). FIG. 42B shows the locking featurein the secured state, in which the inner (kinking) tube has been kinkedso that the tether 3910 is constrained, and cannot slide freely withinthe inner tube 4207. In FIG. 42B, a plug 4201 is pushed forward into thedistal end of the locking feature, compressing the kinking inner tube4207 and securing the tether 3910 into the locked position.

The tether may be cut to remove excess material (e.g., proximal to thelocking feature) either before or after detaching the locking featurefrom the rest of the termination device. As previously described, thetermination device (including the detachable locking feature) may becombined with any of the tether cutters described herein. FIGS. 40A and40B illustrate different tether cutters that may be incorporated into atermination device, including the detachable locking feature. FIG. 40Ashows a termination device with a detachable locking feature similar tothe one shown in FIG. 39. The termination device also includes a tethercutter that is configured as a cutting tube 4002 that has a sharpenedouter edge 4004. The push rood 3915 passes through the cutting tube. Thetermination device also includes guides which guide the tether 3910through the termination device so that it can be positioned for cuttingby the cutting tube 4002. In FIG. 40A, the tether is positioned throughthe termination device so that it can be readily cut by the cutting tubewhen the tube is brought forward (e.g., moving the cutting tubedistally). In FIG. 40A, the cutting tube has at least one edge (e.g.,over half of the cutting tube circumference) so that at least one end ofthe tether (e.g., the end contacting the more proximal end of thetether) is cut by the cutting tube. As described above, other types oftether cutters may be used as well. For example, FIG. 40B shows asimilar tether cutter that is configured to cut the tether when thecutting tube 4010 is drawn proximally. In FIG. 40B, the cutting tube hasa passage 4012 through which the tether 3910 passes, and at least aportion of the cutting tube is sharp 4014. The tether 3910 also passesthrough the wall of the termination device (configured as a catheter inFIGS. 40A and 40B). The end of the tether can be cut by drawing thetether taught after securing the locking feature of the terminationdevice and then moving the cutting tube against the tether so that it iscut.

The exemplary termination devices shown in FIGS. 39 and 40 includepassages or holes through which the tether may couple with the tether3910. As described above, the tether may be threaded into the passagesof the termination device either during use, or before inserting thetermination device. The locking device portion of a termination devicemay include a first passage for engaging the tether on the side (e.g., amore distal side, as shown in FIGS. 42A and 42B) of the locking device,rather than at the distal end, as shown in FIGS. 39-41. In variations ofthe locking feature where the side is longer than width, and the tetherenters the locking feature from the side, the locking feature may beheld against the tissue on the longer side of the locking feature. Thus,the location where the tether first engages the locking feature maydetermine how the locking feature is positioned after being secured to acinched tether.

In some variations, a threading device (e.g., a lasso) may be includedto draw the thread through the termination device, as described abovefor FIGS. 14A and 14B. FIG. 41A shows another variation of a threadingdevice 4104, preloaded into the termination device 4101. The threadingdevice shown comprises a wire that forms a loop (e.g., a lasso), and theflattened loop passes through the holes (or passages) in the terminationdevice. The tether may be passed through the loop, and drawn into thetermination device, as previously described.

In some variations, the termination device may include channels, guidesor passages which direct the tether. For example, FIG. 41B shows aportion of a termination device having a detachable locking feature4107. The termination device includes passages and guides which positionthe tether within the termination device when the tether is coupled tothe termination device. Thus, the tether may be held so that it can besecured, and then cut, using the termination device. FIG. 41C shows anexample of a detachable locking feature of a termination device asdescribed from FIGS. 39-40 in which the locking feature has be securedto the tether and released from the rest of the termination device.

Although FIGS. 39-41 illustrate termination devices having detachablelocking features configured as clamps, any appropriate locking feature(e.g., knot, collars, adhesives, clamps, etc.) may be used, as describedabove.

Furthermore, although the foregoing has been described in some detail byway of illustration and example for purposes of clarity ofunderstanding, it is apparent to those skilled in the art that certainminor changes and modifications will be practiced. Therefore, thedescription and examples should be construed as limiting the scope ofthe invention as described in the claims.

1. A termination device for locking an implantable and cinchable tether,the termination device comprising: an elongate body; and a lockingfeature releasably attached to the distal end of the elongate body, thelocking feature configured to couple to the tether; the locking featurehaving an unsecured state, wherein the tether may move with respect tothe locking feature, and a secured state, wherein the tether is securedby the locking feature. 2-21. (canceled)